22. Using the Command Mode in AutoDock

AutoDock can be run in "command mode", using the " -c " flag thus:

 
% autodock3 -p lig.macro.dpf -l lig.macro.clg -c

When AutoDock has read in the grid maps specified in " lig.macro.dpf ", the program gives the message "COMMAND MODE" and waits for the user to issue a command from the standard input . These commands are described in more detail below.

An alternative way of using the command mode is to edit a file containing the commands you wish AutoDock to execute (say " command.file ") and channel the output to a file (say " command.output "), thus:

 
% autodock3 -p lig.macro.dpf -l lig.macro.clg -c < command.file > command.output &

AutoDock can also be used in a UNIX pipe command. This is valuable when an alternative search procedure is desired. Here, the alternative search procedure issues commands to the standard output, and reads the results from the standard input. In this case, AutoDock is behaving as an energy server for the alternative search-procedure program.

There are eight recognized commands: AutoDock 's command interpreter is not case sensitive.

" eval " Evaluate this state's total energy.
" epdb " Evaluate the energy of the named PDBQ file.
" outc " Output the last state's PDB-formatted Cartesian coordinates.
" oute " Output (non-bond and electrostatic) energy breakdown, by atom.
" traj '' Convert an SA trajectory file into PDB-formatted Cartesian coordinates.
" stop ", " exit ", " quit " Stop the AutoDock command mode interpreter.

eval

Evaluates the total energy of a state defined by the subsequent state variables. This command utilizes the trilinear interpolation routine in AutoDock along with the supplied grid maps defined in the parameter file specified after the ` -p ' flag to return this energy. The internal energy of the ligand is also taken into account, as dictated by the values of the torsion angles supplied in the ntor lines following this eval command line; ntor is the number of torsion angles defined in the ligand PDBQ file, as described in the section "Defining Torsions in AutoDock". The usage of this command is:

eval <float> <float> <float> <float> <float> <float> <float> } Tx, Ty, Tz, Qx, Qy, Qz, Qw (in °)
<float> } ith torsion angle, in °.
:
:
ntor lines.

where: Tx, Ty, Tz are the coordinates of the center of rotation of the ligand; Qx, Qy, Qz is the unit vector describing the direction of rigid body rotation, about which a rotation of angle Qw degrees will be applied. The following ntor lines hold the torsion angles in degrees, given in the same order as described in the AutoDock log file.

epdb

Calculates the energy of the molecule provided in the PDBQ file, thus:

 
epdb lig.pdbq

where: " lig.pdbq " is the PDBQ formatted coordinates of a molecule for which the interaction energy with the macromolecule will be returned. The ` -o ' flag supplied at the AutoDock execution line specifies the old format of PDBQ , with charges in columns 55-61; otherwise it is assumed that the charges are in columns 71-76.

This command is useful when the state variables for a given molecule are not known, e.g. the x-ray crystallographic conformation of the ligand.

outc

Returns the coordinates of the ligand at its current transformed position (in the form of a PDB REMARK). The x , y , z coordinates will be determined by the state variables supplied to the eval command.

oute

Returns the total internal energy of the ligand and the total energy of the complex, at the current state variables. These two REMARK lines are written in PDB format, to the command output channel and the log file.

traj

Convert a simulated annealing " .trj " file into PDBQ format. Usage:

 
traj lig.trj

where " lig.trj " is a simulated annealing (SA) trajectory file written out by an earlier run of AutoDock . This trajectory file contains the state variables for the states sampled during a simulated annealing docking simulation. The torsions are assumed to be in exactly the same order as the input ligand PDBQ file. The torsion angles in the trajectory file are relative to the input ligand's conformation.

See also the Appendix, script " runtrj "; and the next section, "Trajectory Files".

stop, exit, quit

Halts the execution of AutoDock. A value of 0 is returned by the program, and the message "autodock: Successful Completion" is written to the log file and standard error. Timing information is also written. Note: " stop ", " exit " and " quit " are synonymous.