Documentation for the HOLE: 3.0 Control Cards

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3.0 Control of HOLE

When HOLE is run the variables which the user can/must specify are read from the FORTRAN input stream number 5 (defaults to the keyboard). The text output is to stream 6 (normally the screen). The i/o streams should be redirected in the manner normal for the operating system used. For unix machines this is achieved by typing the command:

(nohup nice) hole < control_file.inp > log_file (&)

where hole refers to the executable, your $PATH variable should have been modified so as point to this (see setup section>). The > and < symbols reassign the standard input and output steams to the files specified. control_file.inp is a file containing input information in the format described below and log_file.out is a file which will be created containing text output describing how the run is progressing. (The nice and & put the program into the background with lowered priority). The input is keyworded by the cards described below. In general input is case-insensitive, except for filenames - whose case is not changed on reading. Comments must be preceded by a ! and are not read. Comments can be placed at the end of any line (they will be striped off before the line is interpreted). The user is told of any non-blank line read and not recognized.

3.1 CARDS which MUST be specified:

COORD filename

This specifies the name of co-ordinate file to be used. This must be in Brookhaven protein databank format or something closely approximating this. Both ATOM and HETATM records are read. Note that if water molecules or ions are present in the channel these should normally be deleted from the file.

A new feature in the release is the option to include a wild card (*) in the filename. e.g., coord ab*.pdb will apply hole to all files in the directory whose name starts with ab and ends with .pdb. This intended to aid the analysis of multiple copies of the same molecule - produced during molecular dynamics or other method. The hole procedure will be applied to each file in turn with the same setup conditions (initial point, sampling distance etc.). Graphics files will contain a combination of the individual runs, one after another. Note that the pdb files are read independently so that they need not have an identical number of atoms or atom order etc. (though they should be sufficiently similar for a HOLE run from identical starting conditions to be useful). It may be useful to cut down the information written out to the text output by using a SHORTO card (perhaps with level 2) if multiple files are used. Note that an alternative way to load in multiple files is a direct read from a CHARMm binary dynamics coordinate file - using a CHARMD card.

RADIUS filename

This specifies the name for the file specifying van der Waals radii for each atom. A number of files with different values are supplied with HOLE, see section 5.0. Note that HOLE unlike many programs now knows what a ~ means in unix e.g., the to one can specify a radius file in user mary's directory:

radius ~mary/hole2/rad/simple.rad

CVECT x y z (where x y and z are reals - separated by spaces)

This specified a vector which lies in the direction of the channel/pore.

CPOINT x y z (where x y and z are reals - separated by spaces)

This specifies a point which lies within the channel, for simple channels such as gramicidin results do not show great sensitivity to the exact point taken. An easy way to produce an initial point is to use molecular graphics to find two atoms which lie either side of the pore and to average their co-ordinates.

3.2 CARDS which may be specified

The most useful cards:

PLTOUT filename

specifies the filename for binary 3D QUANTA plot file output. It is normal to give the file the extension ".qpt" for compatibility with other programs. The binary plot file will contain a graphical representation of the hole run. It can be directly displayed in conjuction with the molecule using the QUANTA program, or can be converted for use with other programs (see qpt_conv). If card is NOT present then no graphical output will be produced. The file will contain records consisting of 4 real numbers. If you are interested in other commands please consult Molecular Simulation documentation. The commands used in hole and ancillary programs are:

1.0 x y z

change to colour x.
Extension to standard format used by HOLE if y=-55 then z is an alternative colour number (in range 15 to twenty). The alternative colour number is used by qplot so that HOLE objects are output to different colours: see colours used in HOLE section.

2.0 x y z

move to x y z

3.0 x y z

draw to x y z from present point

4.0 x y z

dot at x y z

5.0 x y z

write character string of length x characters at the current point. This record will be immediated followed by a the character string (length x to be written).
Extension to standard format used by HOLE Program qplot uses the number z as a positioning indicator, if z=

1 the label is placed below the atom to the left

2 the label is centred below the atom

...

5 the label is centred on the atom

...

9 the label is placed above the atom to the right.

An easy way to remember what the integer means is to look at the keypad of any keyboard:

789
456
123

The use of this integer allows the production of pictures in which atom labels are not obscured by the molecule. The program colours when displayed in QUANTA.

Note that:

.qpt files are binary and files produced by one machine may not be correctly read on another (see qpt_conv - option 'A')
dots are not very visible in QUANTA (see qpt_conv - option 'C')
to avoid the final surface appearing like a bone or dumb bell dots are not draw for the first and last sphere centres determined.
the file can be converted for display with other programs (see qpt_conv).

DOTDEN integer

This number controls the density of dots which will be used by the program. A sphere of dots is placed on each centre determined in the Monte Carlo procedure. Only dots which do not lie within any other sphere are considered. The actual number of dots written if therefore controlled by dotden and sample. Dotden should be set to between 5 (few dots per sphere) and 35 (large number of dots per sphere). The default value is 10.

SAMPLE real_no.

The distance between the planes for the sphere centres. Default value is 0.5 angs (this may prove rather long).

SPHPDB filename.

This card specifies the filename for output of the sphere centre information in pdb form. It is useful to assign the filename the qualifier .sph. The co-ordinates are set to the sphere centres and the occupancies are the sphere radii. The file can be imported into molecular graphics programs but are likely to be bonded together in a awful manner (this can be avoided in QUANTA by ***). This can be useful to analyze the distance of particular atoms from the sphere-centre line.

Most usefully .sph files can be used to produce graphical output from a hole run. Although HOLE directly produces .qpt file using the PLTOUT card, this provides a limited number of options for the graphically output. A .sph file can be used together with the sphqpt program to produce more sophisticated results. The seperation has a number of advantages:

Some of the procedures in sphqpt are computationally expensive (notably producing webbed surfaces). Seperation allows you to be sure that you got the HOLE run correct before embarking on producing pretty pictures.

ENDRAD real number

This card can be used to specify the radius above which the program regards a result as an indicating that the end of the pore has been reached. The default value is 5 angstroms.

CAPSULE

Turns on the capusle option. This analyzes the anisotropy of the channel. This also turns on a empirically corrected prediction of the conductance of the channel in KCl: see Section 8 for details.

IGNORE list of 3 character residue types

For fairly obvious reasons, in general it is a good idea to not consider ions or water molecules within an ion channel during a HOLE run. In the bad old days the only way to this was to edit out these records from the input file (specified by a COORD card). Now this can be achieved by specifying an IGNORE card followed by a list of residue types (which are three character strings e.g., alanine = ALA). Any atom whose residue name matches part of the list will be not be read in. Note that wildcards are not allowed in the match (if this is a pressing problem tell me as this could be changed).

To ignore all waters a line like:

ignore hoh tip wat

should appear in the control input file.

2DMAPS filename_root

This card is used to produce files which can be used to make 2d contour maps of the inside surface of a channel. For full details see section 6.5. Note that this card is incompatible with a CAPSULE card.

CHARMD filename

Does multiple HOLE run on positions taken from CHARMm binary dynamics format .DCD trajectory file. N.B. file must have exactly the same number of atoms in exactly the same order as the pdb file specified by the COORD card. Note that if this option is used the pdb file is used as a template only - the coordinates are ignored. Note that structural parameters determined for each individual structure are written in a tagged format so that it is possible to extract the information from the text output file using a grep command. The reading of the file can be controlled by a CHARMS card.

CHARMS integer integer

Controls reading of the CHARMm binary dynamics format .DCD trajectory file specified by the CHARMD card. The first number is the number of positions to be skipped before analysis is to be performed. The second number is the number of positions to be skipped in between each analysis. e.g., Suppose your .DCD file had a position written every 0.5ps and you wanted to analyze the run every 1 ps but ignoring the first 25ps (as this is equilibriation). In this case use a line:
charms 49 2.

Other cards:

DOTOFF

This card will turn off the drawing of a dot surface representation of the hole. If not present then dot surface will be drawn.

SPIKES

The presence of this keyword will cause the program to produce spikes from the surfaces of spheres which go out until line hits an atom's surface rather than dots. This is intended to be useful in looking at channels which are not locally cylindrically symmetrical.

LINON

This will turn on the drawing of lines joining each sphere surface to the two closest atoms. This can be use in showing which atoms cause constrictions in an ion channel. In the previous version of HOLE the default option was to draw closest atom lines and a LINOFF card was specified not to do so - such a card is now ignored.

CENOFF

The presence of this flag will turn off the drawing of the locus of sphere centres as the HOLE sphere squeezes through the channel. This line can be regarded as the centre line for the channel. If a CENOFF card is not present the centre line will be output to the quanta plot file specified by the PLTOUT card.

MCDISP real_no.

Specifies the maximum step length to be taken by the program. The default value 0.1 angstrom.

MCKT real_no.

Specifies the initial "Boltzmann factor" to be used by Monte Carlo routine. The default value 0.1 angstrom. The higher the value the more likely that the routine will jump from any local minimum. Use caution as very high values will produce jumps through the wall of the pore. Generally its a good idea to do a number of initial exploratory runs with high values of MCDISP and MCKT.

MCSTEP integer

This card specifies the number of steps taken for the Metropolis Monte Carlo simulated annealing optimization routine. The default value is 1000 steps which is normally adequate.

RASEED integer

This can be used to provide the random number generator used by the program an initial seed. Normally the seed number is provided by a routine from the time of day. Use this card if you want to repeat a run with different graphics options etc.

SHORTO (optional integer)

Normally during a HOLE run information as to the progress of the run is continuously written to the output stream (which is normally reassigned to a file). It is informative to look at this information if one is doing an initial run as it can reveal such things as whether a sufficiently large number of Monte Carlo steps/step size has been specified. But if one is performing many runs (e.g., repeated runs on a molecular dynamics trajectory) this information just takes up space. By specifying a SHORTO card the amount of information written out can be reduced - the optional integer controlling how much or little is written:

SHORTO 0: Full text output (equivalent of not specifying card!)
SHORTO 1: All text output given except "run in progress" (i.e., detailed contemporary description of what HOLE is doing).
SHORTO 2: Ditto plus no graph type output - only leaving minimum radius and conductance calculations.
SHORTO 3: All text output other than input card mirroring and error messages turned off.

MOLQPT filename

This facility is for people who do not use quanta but want to produce a composite picture of the HOLE surface with the molecule. If you specify a MOLQPT card then a quanta plot file will be written with a stick representation of the molecule written to colour number 1. This file can then be used with the file specified by a PLTOUT card to produce colour/monochrome hardcopy using the program qplot. Quanta users can produce more sophisticated versions such a file using the plot molecules option under the file menu.

STOP