RasMol2 is an X11 windows system tool intended for the visualisation of
proteins and nucleic acids. RasMol requires either an 8bit pseudo colour or
a 24bit (32bit) true colour display. The program reads in a specified
Brookhaven protein databank (PDB) file and determines the connectivity from
the residue information provided. This may then rendered on the screen in a
variety of formats and colour schemes. Currently available molecule
representations include depth-cued wireframes, sticks, space filling `union
of spheres', ball and stick models and protein ribbon diagrams.
The RasMol help facility can be accessed by typing "help " or
"help " from the command line. A complete list of RasMol
commands may be displayed by typing "help commands". A single question
mark may also be used to abbreviate the keyword "help".
Copyright (c) 1992-1994 by Roger Sayle (ras32425@ggr.co.uk)
?commands
?keywords
RasMol allows the execution of interactive commands typed at the "RasMol>"
prompt in the terminal window. Each command must be given on a separate
line. Keywords are case insensitive and may be entered in either upper or
lower case letters. All whitespace characters are ignored except to separate
keywords and their arguments.
The commands/keywords currently recognised by RasMol are given below.
Type "help " for more information on each RasMol function.
backbone colour exit hbond
help load quit reset
restrict ribbon rotate save
script select set show
slab spacefill structure ssbond
translate wireframe write zap
zoom
?backbone
Backbone
Syntax: backbone {}
backbone
The RasMol `backbone' command permits the representation of a polypeptide
backbone as a series of bonds connecting the adjacent alpha carbons of each
amino acid in a chain. The display of these backbone `bonds' is turned on
and off by the command paramater the same as the `wireframe' command. The
command `backbone off' turns off the selected `bonds', and `backbone on' or
with a number turns them on. The number can be used to determine the
cylinder radius of the representation in 0.004 angstrom units. Backbone
objects may be coloured using the RasMol `colour backbone' command. A
parameter value of 500 (2 angstroms) or above results in an "Integer
argument too large" error.
The reserved work backbone is also used as a predefined set ("help sets")
and as a parameter to the `set hbond' and `set ssbond' commands.
?background
Background
Syntax: background
The RasMol `background' command is used to set the colour of the "canvas"
background. The colour may be given as either a colour name or a comma
separated triple of Red, Green and Blue (RGB) components enclosed in square
brackets. Typing the command `help colours' will give a list of the
predefined colour names recognised by RasMol. When running under X Windows,
RasMol also recognises colours in the X server's colour name database.
?center
?centre
Centre
Syntax: center {}
centre {}
The RasMol `centre' command defines the point about which the `rotate'
command and the scroll bars rotate the current molecule. Without a parameter
the centre command resets the centre of rotation to be the centre of gravity
of the molecule. If an atom expression is specified, RasMol rotates the
molecule about the centre of gravity of the set of atoms specified by the
expression. Hence, if a single atom is specified by the expression, that
atom will remain `stationary' during rotations.
Type `help expression' for more information on RasMol atom expressions.
?color
?colour
Colour
Syntax: colour {}
color {}
Colour the atoms (or other objects) of the selected zone. The colour may be
given as either a colour name or a comma separated triple of Red, Green and
Blue (RGB) components enclosed in square brackets. Typing the command `help
colours' will give a list of all the predefined colour names recognised by
RasMol.
Allowed objects are `atoms,' `bonds,' `backbone,' `hbonds,' `ribbons' and
`ssbonds.' If no object is specified, the default keyword `atom' is assumed.
Some colour schemes are defined for certain object types. The colour scheme
`none' can be applied all objects accept atoms, stating that the selected
objects have no colour of their own, but use the colour of their associated
atoms (i.e. the atoms they connect). `Atom' objects can also be coloured by
`amino,' `cpk,' `chain,' `group,' `shapely,' `structure,' `temperature' and
`user' and hydrogen bond objects can also be coloured by `type.' For more
information type `help colour .'
?hbond
?hbonds
HBonds
Syntax: hbonds {}
hbonds
The RasMol `hbond' command is used to represent the hydrogen bonding of the
protein molecule's backbone. This information is useful in assessing the
protein's secondary structure. Hydrogen bonds are represented as either
dotted lines or cylinders between the donor and acceptor residues. The first
time the `hbond' command is used, the program searches the structure of the
molecule to find hydrogen bonded residues and reports the number of bonds to
the user. The command `hbonds on' displays the selected `bonds' as dotted
lines, and the `hbonds off' turns off their display. The colour of hbond
objects may be changed by the `colour hbond' command. Initially, each
hydrogen bond has the colours of its connected atoms.
By default the dotted lines are drawn between the accepting oxygen and the
donating nitrogen. By using the `set hbonds' command the alpha carbon
positions of the appropriate residues may be used instead. This is
especially useful when examining proteins in backbone representation.
?help
Help
Syntax: help { {}}
? { {}
The RasMol `help' command provides on-line help on the given topic.
?load
Load
Syntax: load {pdb}
load alchemy
Load either a Brookhaven Protein Databank (PDB) file or Alchemy(tm) format
file into RasMol2. Only a single PDB file may be loaded at a time. This
command selects all the atoms in the molecule, and sets the default
representation to be a cpk coloured wireframe model.
?exit
?quit
Quit
Syntax: quit
exit
Exit from the RasMol program.
?renum
?renumber
Renumber
Syntax: renumber {{-} }
The RasMol `renumber' command sequentially numbers the residues in a
macromolecular chain. The optional parameter specifies the value of the
first residue in the sequence. By default, this value is one. For proteins,
each amino acid is numbered consecutively from the N terminus to the C
terminus. For nucleic acids, each base is numbered from the 5' terminus to
3' terminus. All chains in the current database are renumbered and gaps in
the original sequence are ignored. The starting value for numbering may be
negative.
?reset
Reset
Syntax: reset
The RasMol `reset' command restores the original viewing transformation and
centre of rotation. The scale is set to it default value, `zoom 100,' the
centre of rotation is set to the geometric centre of the currently loaded
molecule, `centre all,' this centre is translated to the middle of the
screen and the viewpoint set to the default orientation.
This command should not be mistaken for the RasMol `zap' command which
deletes the currently stored molecule, returning the program to its initial
state.
?restrict
Restrict
Syntax: restrict {}
The RasMol `restrict' command both defines the currently active zone of the
molecule and disables the representation of (most of) those parts of the
molecule no longer selected. All subsequent RasMol commands that modify a
molecule's colour or representation effect only the currently selected zone.
The parameter of a `restrict' command is a RasMol atom expression that is
evaluated for every atom of the current molecule. This command is very
similar to the RasMol `select' command, except restrict disables the
`wireframe,' `spacefill' and `backbone' representations in the non-active
zone.
Type "help expression" for more information on RasMol atom expressions.
?ribbon
?ribbons
Ribbons
Syntax: ribbons {}
ribbons
The RasMol `ribbons' command displays the currently loaded protein as a
smooth "ribbon" of depth-cued curves passing along the backbone of the
protein. The ribbon is composed of a number of strands that run parallel to
one another along the peptide plane of each residue. The ribbon is drawn
between each amino acid whose alpha carbon is currently selected. The colour
of the ribbon is changed by the RasMol `colour ribbon' command. If the
current ribbon colour is `none' (the default), the colour is taken from the
alpha carbon at each position along its length.
The width of the ribbon at each position is determined by the optional
parameter in the usual RasMol units. By default this value is 380, which
produces a ribbon 1.52 Angstroms wide. The number of strands in the ribbon
may be altered using the RasMol `set strands' command. The rendering of the
ribbon may also be changed using the `set ribbons' command.
?rotate
Rotate
Syntax: rotate {-}
Rotate the molecule about the specified axis. Permited values for the axis
parameter are "x", "y" and "z". The integer parameter states the angle in
degrees for the structure to be rotated. For the X and Y axes, positive
values move the closest point up and right, and negative values move it down
and left respectively. For the Z axis, a positive rotation acts clockwise
and a negative angle anti-clockwise.
?save
Save
Syntax: save {pdb}
save alchemy
Save the currently selected set of atoms in either a Brookhaven Protein
Database (PDB) or Alchemy(tm) format file. This command should not be
confused with the RasMol `write' command which generates either image or
script files.
?script
Script
Syntax: script
The RasMol `script' command reads a set of commands sequentially from a text
file and executes them. This allows sequences of commonly used commands to
be stored and performed by a single command. A RasMol script file may
contain a further script command up to a maximum "depth" of 10, allowing
compilicated sequences of actions to be executed.
?select
Select
Syntax: select {}
Define the currently active zone of the molecule. All subsequent RasMol
commands that manipulate a molecule or modify its colour or representation,
only effects the currently selected zone. The parameter of a `select'
command is a RasMol expression that is evaluated for every atom of the
current molecule. The currently selected (active) zone of the molecule are
those atoms that cause the expression to evaluate true. To select the whole
molecule use the RasMol command `select all.'
Type "help expression" for more information on RasMol atom expressions.
?set
Set
Syntax: set {}
The RasMol `set' command allows the user to alter various internal program
parameters such as those controlling rendering options. Each parameter has
its own set or permissible parameter options. Typically, ommiting the
paramter option resets that parameter to its default value. A list of valid
parameter names is given below. For more information on each internal
parameter type `help set .'
ambient background bondmode display
hbond hetero hourglass hydrogen
mouse ribbons shadow slabmode
specular specpower ssbonds strands
?show
Show
Syntax: show information
show sequence
The RasMol `show' command display details of the status of the currently
loaded molecule. The command `show information' lists the molecule's name,
classification, PDB code and the number of atoms, chains, groups it
contains. If hydrogen bonding, disulphide bridges or secondary structure
have been determined, the number of hbonds, ssbonds, helices, ladders and
turns are also displayed respectively. The command `show sequence' lists the
residues that compose each chain of the molecule.
?slab
Slab
Syntax: slab {}
slab
The RasMol `slab' command enables, disables or positions the z-clipping
plane of the molecule. The program only draws those portions of the molecule
that are further from the viewer than the slabbing plane. Integer values
range from zero at the very back of the molecule to 100 which is completely
in front of the molecule. Intermediate values determine the percentage of
the molecule to be drawn.
?spacefill
Spacefill
Syntax: spacefill {}
spacefill temperature
spacefill user
spacefill
Represent the currently selected zone as a spacefilling union of spheres
model. An integer parameter may be used to specify the radius of each atom
given in 4nm units. If no parameter is given, each atom is drawn as a sphere
of its Van der Waals radius.
The `temperature' option is used to set the radius of each selected sphere
to the value in the temperature field of the molecule file. A zero or
negative value causes no change in the selected atom. Temperature values
greater than 2.00 are truncated to 2.00 Angstrom radius.
The `user' option allows the radius of the selected spheres to be determined
by matching each atom against optional lines in the input data file. Details
of the wildcard pattern matching used by Raster3D's COLOR records is given
in the manual.
?ssbond
?ssbonds
SSBonds
Syntax: ssbonds {}
ssbonds
The RasMol `ssbonds' command is used to represent the disulphide bridges of
the protein molecule as either dotted lines or cylinders between the
connected cysteines. The first time that the `ssbonds' command is used, the
program searches the structure of the protein to find half-cysteine pairs
(cysteines whose sulphurs are within 3 angstroms of each other) and reports
the number of bridges to the user. The command `ssbonds on' displays the
selected `bonds' as dotted lines, and the command `ssbonds off' disables the
display of ssbonds in the currently selected area. Selection of disulphide
bridges is identical to normal bonds, and may be adjusted using the RasMol
`set bondmode' command. The colour of disulphide bonds may be changed using
the `colour ssbonds' command. By default, each disulphide bond has the
colours of its connected atoms.
By default disulphide bonds are drawn between the sulphur atoms within the
cysteine groups. By using the `set ssbonds' command the position of the
cysteine's alpha carbons may be used instead.
?structure
Structure
Syntax: structure
The RasMol `structure' command calculates secondary structure assignments
for the currently loaded protein. If the original PDB file contained
structural assignment records (HELIX and SHEET) these are discarded.
Initially, the hydrogen bonds of the current molecule are found, if this
hasn't been done already. The secondary structure is the determined using
Kabsch and Sander's DSSP algorithm. Once finished the program reports the
number of helices and ladders found.
?translate
Translate
Syntax: translate {-}
The RasMol `translate' command moves the position of the centre of the
molecule on the screen. The axis parameter specifies along which axis the
molecule is to be moved and the integer parameter specifies the absolute
position of the molecule centre from the middle of the screen. Permited
values for the axis parameter are "x", "y" and "z". Displacement values must
be between -100 and 100 which correspond to moving the current molecule just
off the screen. A positive "x" displacement moves the molecule to the right,
and a positive "y" displacement moves the molecule down the screen. The pair
of commands `translate x 0' and `translate y 0' centres the molecule on the
screen.
?wireframe
Wireframe
Syntax: wireframe {}
wireframe
Represent each bond within the selected zone of the molecule as either a
cylinder or depth-cued vector. If no parameter is given, RasMol draws each
bond as a hither-and-yon shaded narrow vector. An integer parameter
specifies the radius of a cylinder, given in 4nm units, to be used as a
stick bond.
?write
Write
Syntax: write {}
Write the current image to a file in a standard raster format. Currently
supported file formats include "gif" (Compuserve GIF), "ppm" (Portable
Pixmap), "ras" (Sun rasterfile), "ps" and "epsf" (Encapsulated PostScript),
"monops" (Monochrome Encapsulated PostScript) and "bmp" (Microsoft bitmap).
This command should not be confused with the RasMol `save' command which
save the currently selected portion of the molecule.
?zap
Zap
Syntax: zap
Deletes the contents of the current database and resets parameter variables
to their initial default state.
?zoom
Zoom
Syntax: zoom {}
zoom
Change the magnification of the currently displayed image. Boolean
parameters either magnify or reset the scale of current molecule. An integer
parameter between 10 and 200 specifies the desired magnification as a
percentage of the default scale.
?parameters
?set parameters
?internal parameters
Internal Parameters
RasMol has a number of internal parameters that may be modified using the
`set' command. These parameters control a number of program options such as
rendering options and mouse button mappings.
A complete list of internal parameter names is given below. Type "help set
" for more information on each option.
ambient background bondmode display
hbond hetero hourglass hydrogen
mouse ribbons shadow slabmode
specular specpower ssbonds strands
?ambient
?set ambient
Set Ambient
Syntax: set ambient {}
The RasMol `ambient' parameter is used to control the amount of ambient (or
surrounding) light in the scene. The `ambient' value must be between 0 and
100 that controls the percentage intensity of the darkest shade of an
object. For a solid object, this is the intensity of surfaces facing away
from the light source or in shadow. For depth-cued objects this is the
intensity of objects furthest from the viewer.
This parameter is commonly used to correct for monitors with different
"gamma values" (brightness), to change how light or dark a hardcopy image
appears when printed or to alter the feeling of depth for wireframe or
ribbon representations.
?set background
Set Background
Syntax: set background
The RasMol `background' parameter is used to set the colour of the "canvas"
background. The colour may be given as either a colour name or a comma
separated triple of Red, Green, Blue (RGB) components enclosed in square
brackets. Typing the command `help colours' will give a list of the
predefined colour names recognised by RasMol. When running under X Windows,
RasMol also recognises colours in the X server's colour name database.
?bondmode
?set bondmode
Set BondMode
Syntax: set bondmode and
set bondmode or
set bondmode
?set display
Set Display
Syntax: set display selected
set display normal
set display
?set hbonds
Set HBonds
Syntax: set hbonds backbone
set hbonds sidechain
set hbonds
?set hetero
Set Hetero
Syntax: set hetero
set hetero
?set hourglass
Set HourGlass
Syntax: set hourglass
The RasMol `hourglass' parameter allows the user to enable and disable the
use of the `hour glass' cursor used by RasMol to indicate that the program
is currently busy drawing the next frame. The command `set hourglass on'
enable the indicator, whilst `set hourglass off' prevents RasMol from
changing the cursor. This is useful when spinning the molecule, running a
sequence of commands from a script file or using interprocess communication
to execute complex sequences of commands. In these cases a `flashing' cursor
may be distracting.
?set hydrogen
Set Hydrogen
Syntax: set hydrogen
set hydrogen
?set mouse
Set Mouse
Syntax: set mouse rasmol
set mouse insight
set mouse quanta
The RasMol `set mouse' command sets the rotation, translation, scaling and
zooming mouse bindings. The default value is `rasmol' which is suitable for
two button mice (for three button mice the second and third buttons are
synonymous); X-Y rotation is controlled by the first button, and X-Y
translation by the second. Additional functions are controlled by holding a
modifier key on the keyboard. [Shift] and the first button performs scaling,
[shift] and the second button performs Z-rotation, and [control] and the
first mouse button controls the clipping plane. The `insight' and `quanta'
provide the same mouse bindings as other packages for experienced users.
?set ribbons
Set Ribbons
Syntax: set ribbons strands
set ribbons solid
The RasMol `set ribbons' command controls the way that macromolecular
ribbons are displayed. The default value `strands' display macromolecular
ribbons as parallel depth-cued strands that pass along the protein or
nucleic acid backbone. The number of strands in the ribbon may be altered
using the RasMol `set strands' command. The `set ribbons solid' command
renders the macromolecular ribbon as a solid shaded ribbon.
?set shadow
Set Shadow
Syntax: set shadow
The RasMol `set shadow' command enables and disables raytracing of the
currently rendered image. Currently only the spacefilling representation is
shadowed or can cast shadows. Enabling shadowing will automatically disable
the Z-clipping (slabbing) plane using the command `slab off.' Raytracing
typically takes about 10s for a moderately sized protein. It is recommended
that shadowing is normally disabled whilst the molecule is being transformed
or manipulated, and only enabled once an appropiate viewpoint is selected,
to provide a greater impression of depth.
?set slabmode
Set SlabMode
Syntax: set slabmode
The RasMol `slabmode' parameter controls the rendering method of objects cut
by the slabbing (z-clipping) plane. Valid slab modes are "reject", "half",
"hollow", "solid" and "section".
?set specular
Set Specular
Syntax: set specular
The RasMol `set specular' command enables and disables the display of
specular highlights on solid objects drawn by RasMol. Specular highlights
appear as white reflections of the light source on the surface of the
object. The current RasMol implementation uses an approximation function to
generate this highlight.
The specular highlights on the surfaces of solid objects may be altered by
using the specular reflection coefficient, which is altered using the RasMol
`set specpower' command.
?set specpower
Set SpecPower
Syntax: set specpower {}
The `specpower' parameter determines the shininess of solid objects rendered
by RasMol. This value between 0 and 100 adjusts the reflection coeffient
used in specular highlight calculations. The specular highlights are enabled
and disabled by the RasMol `set specular' command. Values around 20 or 30
produce plastic looking surfaces. High values represent more shiny surfaces
such as metals, while lower values produce more diffuse/dull surfaces.
?set ssbonds
Set SSBonds
Syntax: set ssbonds backbone
set ssbonds sidechain
set ssbonds
?set strands
Set Strands
Syntax: set strands {}
The RasMol `strands' parameter controls the number of parallel strands that
are displayed in the ribbon representations of proteins. The permissible
values for this parameter are 1, 2, 3, 4, 5 and 9. The default value is 5.
The number of strands is constant for all ribbons being displayed. However,
the ribbon width (the separation between strands) may be controlled on a
residue by residue basis using the RasMol `ribbons' command.
?expression
?expressions
?atom expressions
Atom Expressions
RasMol atom expressions uniquely identify an arbitrary group of atoms within
a molecule. Atom expressions are composed of either primitive expressions,
(for more details type "help primitives"), predefined sets, (type "help
sets"), comparison operators, ("help comparisons"), `within' expressions,
("help within") or logical (boolean) combinations of the above expression
types.
The logical operators allow complex queries to be constructed out of simpler
ones using the standard boolean connectives `and, or' and `not.' These may
be abbreviated by the symbols "&", "|" and "!" respectively. Parentheses
(brackets) may be used to alter the precedence of the operators. For
convenience, a comma may also be used for boolean disjunction.
The atom expression is evaluated for each atom, hence `protein and backbone'
selects protein bacbone atoms, not the protein and [nucleic] acid backbone
atoms!
Examples: backbone and not helix
within( 800, ser70 )
not (hydrogen or hetero)
not *.FE and hetero
8, 12, 16, 20-28
arg, his, lys
?example expressions
Example Expressions
The following table gives some useful examples of RasMol atom expressions.
For examples of the precise syntax, type "help expressions".
Expression Interpretation
* All atoms
cys Atoms in cysteines
hoh Atoms in heterogenous water molecules
as? Atoms in either asparagine or aspartic acid
*120 Atoms at residue 120 of all chains
*p Atoms in chain P
*.n? Nitrogen atoms
cys.sg Sulphur atoms in cysteine residues
ser70.c? Carbon atoms in serine-70
hem*p.fe Iron atoms in the Heme groups of chain P
?primitive expressions
Primitive Expressions
RasMol primitive expressions are the fundamental building blocks of atom
expressions. There a two basic types of primitive expression. The first type
is used to identify a given residue number or range of residue numbers. A
single residue is identified by its number (position in the sequence), and a
range is specified by lower and upper bounds separated by a hyphen
character. For example `select 5,6,7,8' is also `select 5-8.' Note that this
selects the given residue numbers in all macromolecule chains.
The second type of primitive expression specifies a sequence of fields that
must match for a given atom. The first part specifies a residue (or group of
residues) and an optional second part specifies the atoms within those
residues. The first part consists of a residue name, optionally followed by
a residue number and/or chain identifier. The second part consists of a
period character followed by an atom name. An asterisk may be used as a wild
card for a whole field and a question mark as a single character wildcard.
For examples of RasMol expressions type "help examples".
?comparison
?comparisons
?comparison expressions
?comparison operators
Comparison Operators
Parts of a molecule may also be distinguished using equality, inequality and
ordering operators on their properties. The format of such comparison
expression is a property name, followed by a comparison operator and then an
integer value.
The atom properties that may be used in RasMol are `atomno' for the atom
serial number, `resno' for the residue number, `radius' for the spacefill
radius in RasMol units (or zero if not represented as a sphere) and
`temperature' for the PDB anisotropic temperature value.
The equality operator is denoted either "=" or "==". The inequality operator
as either "<>", "!=" or "/=". The ordering operators are "<" for less than,
"<=" for less than or equal to, ">" for greater than, and ">" for greater
than or equal to.
Examples: resno < 23
temperature >= 900
atomno == 487
?within expressions
Within Expressions
A RasMol `within' expression allows atoms to be selected on their proximity
to another set of atoms. A `within' expression takes two parameters
separated by a comma and surrounded by parenthesis. The first argument is an
integer value called the "cut-off" distance of the within expression and the
second argument is any valid atom expression. The cut-off distance is
expressed in RasMol 0.004 Angstrom units. An atom is selected if it is
within the cut-off distance of any of the atoms defined by the second
argument. This allows complex expressions to be constructed containing
nested `within' expressions.
For example, the command `select within(800,backbone)' selects any atom
within a 3.2 Angstrom radius of any atom in a protein or nucleic acid
backbone. `Within' expressions are particularly usefull for selecting the
atoms around an active site.
?sets
?predefined sets
Predefined Sets
RasMol atom expressions may contain predefined sets. Thsese sets are single
keywords that represent portions of a molecule of interest. Predefined sets
are often abbreviations primitive atom expressions, and in some cases of
selecting areas of a molecule that could not otherwise be distinguished. A
list of the currently predfined sets is given below. Type "help sets
setname" for more information about a given set.
at acidic acyclic aliphatic
alpha amino aromatic backbone
basic buried cg charged
cyclic cystine helix hetero
hydrogen hydrophobic large medium
neutral nucleic polar protein
purine pyrimidine selected sheet
sidechain small surface turn
water
?at set
AT Set
This set contains the atoms in the complementary nucleotides adenosine and
thymidine (A and T respectively). All nucleotides are classified as either
the set `at' or the set `cg' This set is equivalent to the RasMol atom
expressions "a,t" and "nucleic and not cg"
?acidic set
Acidic Set
The set of acidic amino acids. These are the residue types Asp, Glu and Tyr.
All amino acids are classified as either `acidic,' `basic' `or' `neutral.'
This set is equivalent to the RasMol atom expressions "asp, glu, tyr" and
"amino and not (basic or neutral)"
?acyclic set
Acyclic Set
The set of atoms in amino acids not containing a cycle or ring. All amino
acids are classified as either `cyclic' or `acyclic.' This set is equivalent
to the RasMol atom expression "amino and not cyclic"
?aliphatic set
Aliphatic Set
This set contains the aliphatic amino acids. These are the amino acids Ala,
Gly, Ile, Leu and Val. This set is equiavlent to the RasMol atom expression
"ala, gly, ile, leu, val"
?alpha set
Alpha Set
The set of alpha carbons in the protein molecule. This set is approximately
equivalent to the RasMol atom expression "*.CA" This command should not be
confused with the predefined set `helix' which contains the atoms in the
amino acids of the protein's alpha helices.
?amino set
Amino Set
This set contains all the atoms contained in amino acid residues. This is
useful for distinguishing the protein from the nucleic acid and heterogenous
atoms in the current molecule database.
?aromatic set
Aromatic Set
The set of atoms in amino acids containing aromatic rings. These are the
amino acids His, Phe, Trp and Tyr. Because they contain aromatic rings all
members of this set are member of the predefined set `cyclic.' This set is
equivalent to the RasMol atom expressions "his, phe, trp, tyr" and "cyclic
and not pro"
?backbone set
Backbone Set
This set contains the four atoms of each amino acid that form the
polypeptide N-C-C-O backbone of proteins, and the atoms the sugar phosphate
backbone of nucleic acids. Use the RasMol predefined sets `protein' and
`nucleic' to distinguish between the two forms of backbone. Atoms in nucleic
acids and proteins are either `backbone' or `sidechain.' This set is
equivalent to the RasMol expression "(protein or nucleic) and not sidechain
?basic set
Basic Set
The set of basic amino acids. These are the residue types Asp, Glu and Tyr.
All amino acids are classified as either `acidic,' `basic' or `neutral.'
This set is equivalent to the RasMol atom expressions "asp, glu, tyr" and
"amino and not (acidic or neutral)"
?buried set
Buried Set
This set contains the atoms in those amino acids that tend (prefer) to
buried inside protein, away from contact with solvent molecules. This set
refers to the amino acids preference and not the actual solvent acessibility
for the current protein. All amino acids are classified as either `surface'
or `buried.' This set is equivalent to the RasMol atom expression "amino and
not surface"
?cg set
CG Set
This set contains the atoms in the complementary nucleotides cytidine and
guanoine (C and G respectively). All nucleotides are classified as either
the set `at' or the set `cg' This set is equivalent to the RasMol atom
expressions "c,g" and "nucleic and not at"
?charged set
Charged Set
This set contains the charged amino acids. These are the amino acids that
are either `acidic' or `basic.' Amino acids are classified as being either
`charged' or `neutral.' This set is equivalent to the RasMol atom
expressions "acidic or basic" and "amino and not neutral"
?cyclic set
Cyclic Set
The set of atoms in amino acids containing a cycle or rings. All amino acids
are classified as either `cyclic' or `acyclic.' This set consists of the
amino acids His, Phe, Pro, Trp and Tyr. The members of the predefined set
`aromatic' are members of this set. The only cyclic but non-aromatic amino
acid is proline. This set is equivalent to the RasMol atom expressions "his,
phe, pro, trp, tyr" and "aromatic or pro" and "amino and not acyclic"
?cystine set
Cystine Set
This set contains the atoms of cysteine residues that form part of a
disulphide bridge, i.e. half cystines. RasMol automatically determines
disulphide bridges, if neither the predefined set `cystine' nor the RasMol
`ssbonds' command have been used since the molecule was loaded. The set of
free cysteines may be determined using the RasMol atom expression "cys and
not cystine"
?helix set
Helix Set
This set contains all atoms that form part of a protein alpha helix as
determined by either the PDB file author or Kabsch and Sander's DSSP
algorithm. By default, RasMol uses the secondary structure determination
given in the PDB file if it exists. Otherwise, it uses the DSSP algorithm as
used by the RasMol `structure' command.
This command should not be confused with the predefined set `alpha' which
contains the alpha carbon atoms of a protein.
?hetero set
Hetero Set
This set contains all the heterogenous atoms in the molecule. These are the
atoms described by HETATM entries in the PDB file. These typically contain
water, cofactors and other solvents and ligands. The RasMol predefined set
`water' is often used to partition this set.
?hydrogen set
Hydrogen Set
This predefined set contains all the hydrogen and deuterium atoms of the
current molecule.
?hydrophobic set
Hydrophobic Set
This set contains all the hydrophobic amino acids. These are the amino acids
Ala, Leu, Val, Ile, Pro, Phe, Met and Trp. All amino acids are classified as
either `hydrophobic' or `polar.' This set is equivalent to the RasMol atom
expressions "ala, leu, val, ile, pro, phe, met, trp" and "amino and not
polar"
?large set
Large Set
All amino acids are classified as either `small,' `medium' or `large.' This
set is equivalent to the RasMol atom expression "amino and not (small or
medium)"
?medium set
Medium Set
All amino acids are classified as either `small,' `medium' or `large.' This
set is equivalent to the RasMol atom expression "amino and not (large or
small)"
?neutral set
Neutral Set
The set of neutral amino acids. All amino acids are classified as either
`acidic,' `basic' `or' `neutral.' This set is equivalent to the RasMol atom
expression "amino and not (acidic or basic)"
?nucleic set
Nucleic Set
The set of all atoms in nucleic acids.
?polar set
Polar Set
This set contains the polar amino acids. All amino acids are classified as
either `hydrophobic' or `polar.' This set is equivalent to the RasMol atom
expression "amino and not hydrophobic"
?protein set
Protein Set
The set of all atoms in proteins. This consists of the RasMol predefined set
`amino' and common post-translation modifications.
?purine set
Purine Set
The set of purine nucleotides. These are the bases adenosine and guanosine
(A and G respectively). All nucleotides are either `purines' or
`pyrimidines.' This set is equivalent to the RasMol atom expressions "a,g"
and "nucleic and not purine"
?pyrimidine set
Pyrimidine Set
The set of pyrimidine nucleotides. These are the bases cytidine and
thymidine (C and T respectively). All nucleotides are either `purineset
purines' or `pyrimidines.' This set is equivalent to the RasMol atom
expressions "c,t" and "nucleic and not pyrimidine"
?selected set
Selected Set
This set contains the set of atoms in the currently active zone. The
currently active zone is defined by the preceding `select' or `restrict'
command and not the atom expression containing the `selected' keyword.
?sheet set
Sheet Set
This set contains all atoms that form part of a protein beta sheet as
determined by either the PDB file author or Kabsch and Sander's DSSP
algorithm. By default, RasMol uses the secondary structure determination
given in the PDB file if it exists. Otherwise, it uses the DSSP algorithm as
used by the RasMol `structure' command.
?sidechain set
Sidechain Set
This set contains the functional sidechains of any amino acids and the base
of each nucleotide. These are the atoms not part of the polypeptide N-C-C-O
backbone of proteins or the sugar phosphate backbone of nucleic acids. Use
the RasMol predefined sets `protein' and `nucleic' to distinguish between
the two forms of sidechain. Atoms in nucleic acids and proteins are either
`backbone' or `sidechain.' This set is equivalent to the RasMol expression
"(protein or nucleic) and not backbone
?small set
Small Set
All amino acids are classified as either `small,' `medium' or `large.' This
set is equivalent to the RasMol atom expression "amino and not (medium or
large)"
?surface set
Surface Set
This set contains the atoms in those amino acids that tend (prefer) to be on
the surface of proteins, in contact with solvent molecules. This set refers
to the amino acids preference and not the actual solvent acessibility for
the current protein. All amino acids are classified as either `surface' or
`buried.' This set is equivalent to the RasMol atom expression "amino and
not buried"
?turn set
Turn Set
This set contains all atoms that form part of a protein turns as determined
by either the PDB file author or Kabsch and Sander's DSSP algorithm. By
default, RasMol uses the secondary structure determination given in the PDB
file if it exists. Otherwise, it uses the DSSP algorithm as used by the
RasMol `structure' command.
?water set
Water Set
This set contains all the heterogenous water molecules in the current
database. A large number of water molecules are sometimes associated with
protein and nucleic acid structures determined by X-ray crystallography.
These atoms tend to clutter an image.
?colors
?colours
?color schemes
?colour schemes
?color names
?colour names
?predefined colors
?predefined colours
Colour Schemes
The RasMol `colour' command allows different objects (such as atoms, bonds
and ribbon segments) to be given a specified colour. Typically this colour
is either a RasMol predefined colour name or an RGB triple. Additionally
RasMol also supports `amino,' `chain,' `group,' `shapely,' `structure,'
`temperature,' `user' and `hbond type' colour schemes. The currently
predefined colour names are listed below with their corresponding RGB
triplet.
blue [0,0,255] black [0,0,0]
cyan [0,255,255] green [0,255,0]
greenblue [46,139,87] magenta [255,0,255]
orange [255,165,0] purple [160,32,240]
red [255,0,0] redorange [255,69,0]
violet [238,130,238] white [255,255,255]
yellow [255,255,0]
?color amino
?colour amino
?amino colours
Amino Colours
The RasMol `amino' colour scheme colours amino acids according to
traditional amino acid properties. The purpose of colouring is to identify
amino acids in an unusual or surprising environment. The outer parts of a
protein are polar are visible (bright) colours and non-polar residues
darker. Most colours are hallowed by tradition. This colour scheme is
similar to the `shapely' scheme.
ASP,GLU bright red [230,10,10] CYS,MET yellow [230,230,0]
LYS,ARG blue [20,90,255] SER,THR orange [250,150,0]
PHE,TYR mid blue [50,50,170] ASN,GLN cyan [0,220,220]
GLY light grey [235,235,235] LEU,VAL,ILE green [15,130,15]
ALA dark grey [200,200,200] TRP pink [180,90,180]
HIS pale blue [130,130,210] PRO flesh [220,150,130]
?chain
?color chain
?colour chain
?chain colours
Chain Colours
The RasMol `chain' colour scheme assigns each macromolecular chain a unique
colour. This colour scheme is particularly usefull for distinguishing the
parts of multimeric structure or the individual `strands' of a DNA chain.
?cpk
?color cpk
?colour cpk
?cpk colours
CPK Colours
The RasMol `cpk' colour scheme is based upon the colours of the popular
plastic spacefilling models which were developed by Corey, Pauling and later
improved by Kultun. This colour scheme colour `atom' objects by the atom
(element) type. This is the scheme conventionally used by chemists. The
assignment of element type to colours is given below.
Carbon light grey Chlorine green
Oxygen red Bromine, Zinc brown
Hydogen white Sodium blue
Nitrogen light blue Iron purple
Sulphur yellow Calcium, Metals dark grey
Phosphorous orange Unknown deep pink
?group
?color group
?colour group
?group colours
Group Colours
The RasMol `group' colour scheme colour codes residues by their position in
a macromolecular chain. Each chain is drawn as a smooth spectrum from blue
through green, yellow and orange to red. Hence the N terminus of proteins
and 5' terminus of nucleic acids are coloured red and the C terminus of
proteins and 3' terminus of nucleic acids are drawn in blue. If a chain has
a large number of heterogenous molecules associated with it, the
macromolecule may not be drawn in the full `range' of the spectrum.
?shapely
?shapely colors
?shapely colours
?shapely colours
Shapely Colours
The RasMol `shapely' colour scheme colour codes residues by amino acid
property. This scheme is based upon Bob Fletterick's "Shapely Models". Each
amino acid and nucleic acid residue is given a unique colour. The `shapely'
colour scheme is used by David Bacon's Raster3D program. This colour scheme
is similar to the `amino' colour scheme.
?color structure
?colour structure
?structure colours
Structure Colours
The RasMol `structure' colour scheme colours the molecule by protein
secondary structure. Alpha helices are coloured magenta, [240,0,128], beta
sheets are coloured yellow, [255,255,0], turns are coloured pale blue,
[96,128,255] and all other residues are coloured white. The secondary
structure is either read from the PDB file (HELIX and SHEET records), if
available, or determined using Kabsch and Sander's DSSP algorithm. The
RasMol `structure' command may be used to force DSSP's structure assignment
to be used.
?temperature
?color temperature
?colour temperature
?temperature colours
Temperature Colours
The RasMol `temperature' colour scheme colour codes each atom according to
the anisotropic temperature (beta) value stored in the PDB file. Typically
this gives a measure of the mobility/uncertainty of a given atom's position.
High values are coloured in warmer (red) colours and lower values in colder
(blue) colours. This feature is often used to associate a "scale" value
[such as amino acid variability in viral mutants] with each atom in a PDB
file, and colour the molecule appropriately.
?user
?color user
?colour user
?user colours
User Colours
The RasMol `user' colour scheme allows RasMol to use the colour scheme
stored in the PDB file. The colours for each atom are stored in COLO records
placed in the PDB data file. This convention was introducted by David
Bacon's Raster3D program.
?type
?color type
?colour type
?hbond type colours
HBond Type Colours
The RasMol `type' colour scheme applies only to hydrogen bonds, hence is
used in the command "colour hbonds type" This colour scheme colour codes
each hydrogen bond according to the distance along a protein chain between
hydrogen bond donor and acceptor. This schematic representation was
introduced by Belhadj-Mostefa and Milner-White. This representation gives a
good insight into protein secondary structure (hbonds forming alpha helices
appear red, those forming sheets appear yellow and those forming turns
appear magenta).
Offset Colour Triple
+2 white [255,255,255]
+3 magenta [255,0,255]
+4 red [255,0,0]
+5 orange [255,165,0]
-3 cyan [0,255,255]
-4 green [0,255,0]
default yellow [255,255,0]
?codes
?amino codes
?amino acid codes
Amino Acid Codes
The following table lists the names, single letter and three letter codes of
each of the amino acids.
Alanine A ALA Arginine R ARG
Asparagine N ASN Aspartic acid D ASP
Cysteine C CYS Glutamic acid E GLU
Glutamine Q GLN Glycine G GLY
Histidine H HIS Isoleucine I ILE
Leucine L LEU Lysine K LYS
Methionine M MET Phenylalanine F PHE
Proline P PRO Serine S SER
Threonine T THR Tryptophan W TRP
Tyrosine Y TYR Valine V VAL
?boolean
?booleans
?boolean expression
?boolean expressions
Booleans
A boolean parameter is a truth value. Valid boolean values are `true' and
`false', and their synonyms `on' and `off'. Boolean parameters are commonly
used by RasMol to either enable or disable a representation or option.
