[gmx-users] Re: Re: trjconv and missing chain identifier
una.bjarnadottir at ucd.ie
Mon Mar 5 11:06:19 CET 2007
Hi Mark and other users,
Thanks for your reply and apologies for my English.
If the chain identifiers are discarded by gromacs why do I than get
from trjconv an output file looking like this when having more than one
chain in the .trr file like in this example (part of .pdb file)
ATOM 2776 O1 PHE A 336 32.109 64.621 29.258 1.00 0.00
ATOM 2777 O2 PHE A 336 30.372 64.241 30.505 1.00 0.00
ATOM 2778 N THR B 337 60.139 23.423 46.095 1.00 0.00
ATOM 2779 CA THR B 337 58.765 23.151 45.661 1.00 0.00
but not when I have only one chain in the .trr like in this example
(part of .pdb file).
ATOM 2776 O1 PHE 336 41.051 55.857 23.785 1.00 0.00
ATOM 2777 O2 PHE 336 42.809 56.115 22.532 1.00 0.00
VMD can unfortunately not do what I need so is there no way to get the
chain identifier like in the first example?
Best regards, Una
Una Bjarnadottir wrote:
> Dear Users,
> I'm converting trajectory files into .pdb files and when there is only
> the protein chain in them i.e. only the protein but not ligand or
> it does not set any chain identifier to the output .pdb files. But
> is a ligand and inhibitor in them the output will have chains A-B-C.
> I tried whatif to add the chain identifier but it can't read the big
> The chain identifier is necessary in some graphics programs so I really
> need this.
> Hope you can help, it will be highly appreciated.
gromacs discards chain identifiers from PDB files when it reads them
with pdb2gmx and will not re-create them.
Probably free software like VMD http://www.ks.uiuc.edu/Research/vmd/ can
do what you need without these chain problems, rather than the graphics
program you're planning to use.
I appreciate that English may not be your first language, but please do
consider proof-reading your posts and/or using a spell-checker before
you send. People on this list are much more likely to help you if you
make it easy for them to do so, rather than work at trying to piece
together your problem.
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