SYNOPSIS
do_dssp -f traj.xtc -s topol.tpr -n index.ndx -ssdump ssdump.dat -map ss.map -o ss.xpm -sc scount.xvg -a area.xpm -ta totarea.xvg -aa averarea.xvg -[no]h -[no]version -nice int -b time -e time -dt time -tu enum -[no]w -xvg enum -sss stringDESCRIPTION
do_dssp reads a trajectory file and computes the secondary structure for each time frame calling the dssp program. If you do not have the dssp program, get it from http://swift.cmbi.ru.nl/gv/dssp. do_dssp assumes that the dssp executable is located in /usr/local/bin/dssp. If this is not the case, then you should set an environment variable DSSP pointing to the dssp executable, e.g.:
setenv DSSP /opt/dssp/bin/dssp
The structure assignment for each residue and time is written to an .xpm matrix file. This file can be visualized with for instance xv and can be converted to postscript with xpm2ps. Individual chains are separated by light grey lines in the .xpm and postscript files. The number of residues with each secondary structure type and the total secondary structure ( -sss) count as a function of time are also written to file ( -sc).
Solvent accessible surface (SAS) per residue can be calculated, both in absolute values (A2) and in fractions of the maximal accessible surface of a residue. The maximal accessible surface is defined as the accessible surface of a residue in a chain of glycines. Note that the program g_sas can also compute SAS and that is more efficient.
Finally, this program can dump the secondary structure in a special file ssdump.dat for usage in the program g_chi. Together these two programs can be used to analyze dihedral properties as a function of secondary structure type.
FILES
-f traj.xtc InputTrajectory: xtc trr trj gro g96 pdb cpt
-s topol.tpr
Input
Structure+mass(db): tpr tpb tpa gro g96 pdb
-n index.ndx
Input, Opt.
Index file
-ssdump ssdump.dat
Output, Opt.
Generic data file
-map ss.map
Input, Lib.
File that maps matrix data to colors
-o ss.xpm
Output
X PixMap compatible matrix file
-sc scount.xvg
Output
xvgr/xmgr file
-a area.xpm
Output, Opt.
X PixMap compatible matrix file
-ta totarea.xvg
Output, Opt.
xvgr/xmgr file
-aa averarea.xvg
Output, Opt.
xvgr/xmgr file
OTHER OPTIONS
-[no]hnoPrint help info and quit
-[no]versionno
Print version info and quit
-nice int 19
Set the nicelevel
-b time 0
First frame (ps) to read from trajectory
-e time 0
Last frame (ps) to read from trajectory
-dt time 0
Only use frame when t MOD dt = first time (ps)
-tu enum ps
Time unit: fs, ps, ns, us, ms or s
-[no]wno
View output .xvg, .xpm, .eps and .pdb files
-xvg enum xmgrace
xvg plot formatting: xmgrace, xmgr or none
-sss string HEBT
Secondary structures for structure count