[gmx-users] simulating two peptides in a box

kartik mehra hrahesh at gmail.com
Mon Jul 7 20:42:27 CEST 2008


Dear Justin,

1. They are the same protein ( 2 copies of the same protein)

2. The order in the .gro file seems fine... Basically it lists the
co-ordinates of a single copy of  peptide and then the solvent molecule ...
I presume since the .top file has 4 copies of the same molecule, this is how
the .gro file should look ?

3. Also is there an easier way of dealing with the modification of number of
solvent molecules ( since the co-ordinates involve a factor of 3 arising out
of the description of SPC atoms ... )





Thanks



>
> -
> From: Justin A. Lemkul <jalemkul at vt.edu>
> Date: Mon, Jul 7, 2008 at 11:30 AM
> Subject: Re: [gmx-users] simulating two peptides in a box
> To: Discussion list for GROMACS users <gmx-users at gromacs.org>
>
>
>
>
> kartik mehra wrote:
>
>>
>>    Dear Gromacs USers
>>
>>
>> 1. Please disregard the previous mail which was sent from a different
>> email id ....
>>
>> 2. I have copied the relevant portion here ...( previous mail had a wrong
>> command ...I have copied the actual command here)
>>
>> Dear Justin,
>>
>>  Here is the exact error message : ( Here I have tried to simulate 4
>> protein molecules in a box ...basically I am looking at multiple molecule
>> interactions )
>>
>> *grompp  -f em.mdp -c nt17_sol.gro -o nt17_em.tpr -p nt17.top*
>>
>> *checking input for internal consistency...
>> calling /usr/bin/cpp...
>> processing topology...
>> Generated 279 of the 1225 non-bonded parameter combinations
>> Excluding 3 bonded neighbours for Protein 4
>> Excluding 2 bonded neighbours for SOL 8813
>> NOTE:
>>  System has non-zero total charge: 4.000000e+00
>>
>> processing coordinates...
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (N - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (H1 - HW1)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (H2 - HW2)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (H3 - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CA - HW1)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CB - HW2)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CG - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (SD - HW1)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CE - HW2)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (C - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (O - HW1)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (N - HW2)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (H - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CA - HW1)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CB - HW2)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (C - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (O - HW1)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (N - HW2)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (H - OW)
>> Warning: atom names in nt17.top and nt17_sol.gro don't match (CA - HW1)
>> (more than 20 non-matching atom names)
>> WARNING 1 [file "nt17.top", line 1126]:
>>  534 non-matching atom names
>>  atom names from nt17.top will be used
>>  atom names from nt17_sol.gro will be ignored
>>
>> double-checking input for internal consistency...
>> renumbering atomtypes...
>> converting bonded parameters...
>> #      BONDS:   17626
>> #   G96BONDS:   716
>> #     ANGLES:   8813
>> #  G96ANGLES:   1040
>> #      PDIHS:   372
>> #      IDIHS:   320
>> #       LJ14:   1104
>> initialising group options...
>> processing index file...
>> Analysing residue names:
>> Opening library file
>> /usr/local/gromacs/3.3.1/64/gnu/ib/share/gromacs/top/aminoacids.dat
>> There are:  8813      OTHER residues
>> There are:    68    PROTEIN residues
>> There are:     0        DNA residues
>> Analysing Protein...
>> Analysing Other...
>> Making dummy/rest group for T-Coupling containing 27151 elements
>> Making dummy/rest group for Acceleration containing 27151 elements
>> Making dummy/rest group for Freeze containing 27151 elements
>> Making dummy/rest group for Energy Mon. containing 27151 elements
>> Making dummy/rest group for VCM containing 27151 elements
>> Number of degrees of freedom in T-Coupling group rest is 81450.00
>> Making dummy/rest group for User1 containing 27151 elements
>> Making dummy/rest group for User2 containing 27151 elements
>> Making dummy/rest group for XTC containing 27151 elements
>> Making dummy/rest group for Or. Res. Fit containing 27151 elements
>> Making dummy/rest group for QMMM containing 27151 elements
>> T-Coupling       has 1 element(s): rest
>> Energy Mon.      has 1 element(s): rest
>> Acceleration     has 1 element(s): rest
>> Freeze           has 1 element(s): rest
>> User1            has 1 element(s): rest
>> User2            has 1 element(s): rest
>> VCM              has 1 element(s): rest
>> XTC              has 1 element(s): rest
>> Or. Res. Fit     has 1 element(s): rest
>> QMMM             has 1 element(s): rest
>> Checking consistency between energy and charge groups...
>> Calculating fourier grid dimensions for X Y Z
>> Using a fourier grid of 60x60x60, spacing 0.118 0.118 0.118
>> writing run input file...
>>
>> Back Off! I just backed up nt17_em.tpr to ./#nt17_em.tpr.4#
>> There was 1 warning*
>>
>> Any suggestions would be appreciated .. Also I do believe that the order
>> might be a problem..but isnt an inclusion of the no .of molecules meant to
>> take care of that ?
>>
>> Thanks
>>
>>
>
> OK, that's clear now.  What's happening is that grompp is finding water
> molecules where it should be finding protein.  Including a "number of
> protein molecules" does not automatically fix anything, necessarily.  Again,
> I ask, are your proteins the same?
>
> If they are different, you will need to have a mechanism something like:
>
> #include "Protein_A.itp"
> #include "Protein_B.itp"
>
> #include "spc.itp"
>
> #include "ions.itp"
>
> to get the desired behavior.
>
> Bottom line - check the order of the molecules in your .gro file, you'll
> likely find that the order is not the same as the topology expects it.
>
> -Justin
>
>
>>
>>    ---------- Forwarded message ----------
>>    From: *Justin A. Lemkul* <jalemkul at vt.edu <mailto:jalemkul at vt.edu>>
>>    Date: Mon, Jul 7, 2008 at 10:50 AM
>>    Subject: Re: [gmx-users] simulating two peptides in a box
>>    To: Discussion list for GROMACS users <gmx-users at gromacs.org
>>    <mailto:gmx-users at gromacs.org>>
>>
>>
>>    Several questions come to mind, aside from trying to sift through
>>    your interpretation of error messages.  Hint: always show your
>>    exact command, followed by the relevant portion of the screen
>>    output; that way we don't have to guess what you've been up to :-)
>>
>>    1. Do you have two different proteins, or are they the same?  If
>>    they are different, changing the number of Protein molecules in
>>    your topology will not be correct.  If they are the same, this is
>>    fine.
>>
>>    2. Does the order of your topology follow the order of the
>>    coordinate file?  When you get warnings about non-matching atom
>>    names, you should be alert that something has gone wrong.
>>
>>    -Justin
>>
>>    kartik mehra wrote:
>>
>>        Dear GMX Users,
>>
>>        I am trying to set up a simulation box with two proteins. I
>>        have perused the archives about the methodology of doing so. I
>>        tried the recommended option of changing the number of protein
>>        molecules in the topology file to 2. However when I run grompp
>>        after editconf and genbox, I get warning that the number of co
>>        -ordinates do not match (since I had not updated the number of
>>        solvent molecules ...) After updating the number of solvent
>>        molecules, when I try running grompp again, it shows a warning
>>        that the 23644 atom names do not match in top and gro files
>>        and that atom names from top files are being chosen .
>>
>>        Upon subsequent mdrun, the system explodes after a 1-4
>>        interaction warning.
>>
>>        I was wondering whether anyone could help me out on this ... I
>>        do understand that the topic has been discussed pretty often
>>        but would appreciate any help ...
>>
>>
>>        Cheers
>>
>>        Kartik
>>
>>        PS: I have not yet tried the other suggestion of translation
>>        and rotation followed by concatenating the two files
>>
>>
>>
>>  ------------------------------------------------------------------------
>>
>>        _______________________________________________
>>        gmx-users mailing list    gmx-users at gromacs.org
>>        <mailto:gmx-users at gromacs.org>
>>        http://www.gromacs.org/mailman/listinfo/gmx-users
>>        Please search the archive at http://www.gromacs.org/search
>>        before posting!
>>        Please don't post (un)subscribe requests to the list. Use the
>>        www interface or send it to gmx-users-request at gromacs.org
>>        <mailto:gmx-users-request at gromacs.org>.
>>        Can't post? Read http://www.gromacs.org/mailing_lists/users.php
>>
>>
>>    --    ========================================
>>
>>    Justin A. Lemkul
>>    Graduate Research Assistant
>>    Department of Biochemistry
>>    Virginia Tech
>>    Blacksburg, VA
>>    jalemkul[at]vt.edu <http://vt.edu> | (540) 231-9080
>>    http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>>
>>    ========================================
>>
>>    _______________________________________________
>>    gmx-users mailing list    gmx-users at gromacs.org
>>    <mailto:gmx-users at gromacs.org>
>>    http://www.gromacs.org/mailman/listinfo/gmx-users
>>    Please search the archive at http://www.gromacs.org/search before
>>    posting!
>>    Please don't post (un)subscribe requests to the list. Use the www
>>    interface or send it to gmx-users-request at gromacs.org
>>    <mailto:gmx-users-request at gromacs.org>.
>>    Can't post? Read http://www.gromacs.org/mailing_lists/users.php
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> gmx-users mailing list    gmx-users at gromacs.org
>> http://www.gromacs.org/mailman/listinfo/gmx-users
>> Please search the archive at http://www.gromacs.org/search before
>> posting!
>> Please don't post (un)subscribe requests to the list. Use the www
>> interface or send it to gmx-users-request at gromacs.org.
>> Can't post? Read http://www.gromacs.org/mailing_lists/users.php
>>
>
> --
> ========================================
>
> Justin A. Lemkul
> Graduate Research Assistant
> Department of Biochemistry
> Virginia Tech
> Blacksburg, VA
> jalemkul[at]vt.edu | (540) 231-9080
> http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>
> ========================================
>
> _______________________________________________
> gmx-users mailing list    gmx-users at gromacs.org
> http://www.gromacs.org/mailman/listinfo/gmx-users
> Please search the archive at http://www.gromacs.org/search before posting!
> Please don't post (un)subscribe requests to the list. Use the www interface
> or send it to gmx-users-request at gromacs.org.
> Can't post? Read http://www.gromacs.org/mailing_lists/users.php
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-users/attachments/20080707/9325f5a0/attachment.html>


More information about the gromacs.org_gmx-users mailing list