[gmx-users] topology for small peptide using amber03

Mark Abraham mark.j.abraham at gmail.com
Thu Nov 28 10:21:48 CET 2013


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Mark
On Nov 28, 2013 4:26 AM, "kolnkempff" <kolnkempff at gmail.com> wrote:

> /I am trying to use pdb2gmx to get a topology for a very simple peptide
> that
> has just three components:  an ACE residue followed by phenylananine
> followed by NME
> I've read through the Duan article and it seems that amber03 should be
> ideal
> for this.  The pdb file I'm using came from a quantum simulation using
> gamess.  I went in by hand to label each atom as belonging to ACE, PHE, or
> NME.
>
> Try #1  All atoms listed as "HETATM"/
>
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/aminoacids.r2b
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/dna.r2b
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/rna.r2b
> Reading apn1.pdb...
> WARNING: all CONECT records are ignored
> Read 'UNNAMED', 32 atoms
> Analyzing pdb file
> Splitting chemical chains based on TER records or chain id changing.
> There are 1 chains and 0 blocks of water and 1 residues with 32 atoms
>
>   chain  #res #atoms
>   1 ' '     3     32
>
> All occupancies are one
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/atomtypes.atp
> Atomtype 1
> Reading residue database... (amber03)
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/aminoacids.rtp
> Residue 93
> Sorting it all out...
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/dna.rtp
> Residue 109
> Sorting it all out...
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/rna.rtp
> Residue 125
> Sorting it all out...
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/aminoacids.hdb
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/dna.hdb
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/rna.hdb
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/aminoacids.n.tdb
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/aminoacids.c.tdb
> Processing chain 1 (32 atoms, 3 residues)
> Identified residue PHE1 as a starting terminus.
> Identified residue NME1 as a ending terminus.
> 8 out of 8 lines of specbond.dat converted successfully
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/aminoacids.arn
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/dna.arn
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/amber03.ff/rna.arn
>
> -------------------------------------------------------
> Program pdb2gmx, VERSION 4.6.4
> Source code file: /home/koln/bin/gromacs-4.6.4/src/kernel/pdb2gmx.c, line:
> 727
>
> Fatal error:
> Atom H in residue ACE 1 was not found in rtp entry ACE with 6 atoms
> while sorting atoms.
>
> /I looked at aminoacids.rtp which lists [ACE] as having 6 atoms.  I went
> ahead and checked [PHE] and [NME] and I have the same number and type of
> atoms as they do.
>
> Try #2.  After looking at a pdb file for a small neuropeptide I decided to
> try labeling everything as "ATOM" rather than 'HETATM"
> [first part is same as before]/
>
> Warning: Starting residue E1 in chain not identified as Protein/RNA/DNA.
> Problem with chain definition, or missing terminal residues.
> This chain does not appear to contain a recognized chain molecule.
> If this is incorrect, you can edit residuetypes.dat to modify the behavior.
> 8 out of 8 lines of specbond.dat converted successfully
>
> -------------------------------------------------------
> Program pdb2gmx, VERSION 4.6.4
> Source code file: /home/koln/bin/gromacs-4.6.4/src/kernel/resall.c, line:
> 642
>
> Fatal error:
> Residue 'E' not found in residue topology database
>
> /Try #3.  I labeled the phenylalanine atoms as "ATOM" and the terminal ACE
> and NME atoms as "HETATM"/
> Warning: Starting residue E1 in chain not identified as Protein/RNA/DNA.
> Identified residue ACE1 as a starting terminus.
> Identified residue NME1 as a ending terminus.
> 8 out of 8 lines of specbond.dat converted successfully
>
> -------------------------------------------------------
> Program pdb2gmx, VERSION 4.6.4
> Source code file: /home/koln/bin/gromacs-4.6.4/src/kernel/resall.c, line:
> 642
>
> Fatal error:
> Residue 'E' not found in residue topology database
>
> /I have no idea where "Residue 'E'" came from.
> Since the third try seems to be closest to "working", that's the one I am
> including below.
>
> Thanks in advance for whatever help you can offer.
>
> Koln/
>
> pdb file:COMPND    UNNAMED
> AUTHOR    GENERATED BY OPEN BABEL 2.3.1
> ATOM    1  N   PHE     1       0.720   0.859  -0.499  1.00  0.00
> N
> ATOM    2  C   PHE     1       0.760  -0.439   0.174  1.00  0.00
> C
> ATOM    3  C   PHE     1       2.125  -1.161   0.111  1.00  0.00
> C
> ATOM    4  O   PHE     1       2.253  -2.263   0.634  1.00  0.00
> O
> ATOM    5  H   PHE     1       0.176   0.905  -1.352  1.00  0.00
> H
> ATOM    6  H   PHE     1       0.585  -0.253   1.240  1.00  0.00
> H
> ATOM    7  C   PHE     1      -0.336  -1.383  -0.373  1.00  0.00
> C
> ATOM    8  C   PHE     1      -1.743  -0.858  -0.186  1.00  0.00
> C
> ATOM    9  H   PHE     1      -0.200  -2.340   0.138  1.00  0.00
> H
> ATOM   10  H   PHE     1      -0.145  -1.567  -1.440  1.00  0.00
> H
> ATOM   11  C   PHE     1      -4.354   0.139   0.179  1.00  0.00
> C
> ATOM   12  C   PHE     1      -2.316  -0.794   1.094  1.00  0.00
> C
> ATOM   13  C   PHE     1      -2.504  -0.416  -1.277  1.00  0.00
> C
> ATOM   14  C   PHE     1      -3.799   0.078  -1.100  1.00  0.00
> C
> ATOM   15  C   PHE     1      -3.607  -0.301   1.276  1.00  0.00
> C
> ATOM   16  H   PHE     1      -1.744  -1.138   1.954  1.00  0.00
> H
> ATOM   17  H   PHE     1      -2.086  -0.476  -2.281  1.00  0.00
> H
> ATOM   18  H   PHE     1      -4.373   0.412  -1.961  1.00  0.00
> H
> ATOM   19  H   PHE     1      -4.033  -0.263   2.276  1.00  0.00
> H
> ATOM   20  H   PHE     1      -5.362   0.519   0.320  1.00  0.00
> H
> HETATM   21  C   ACE     1       0.873   2.036   0.208  1.00  0.00
> C
> HETATM   22  O   ACE     1       1.301   2.055   1.353  1.00  0.00
> O
> HETATM   23  C   ACE     1       0.484   3.302  -0.540  1.00  0.00
> C
> HETATM   24  H   ACE     1       1.253   4.060  -0.375  1.00  0.00
> H
> HETATM   25  H   ACE     1      -0.451   3.685  -0.116  1.00  0.00
> H
> HETATM   26  H   ACE     1       0.345   3.153  -1.616  1.00  0.00
> H
> HETATM   27  N   NME     1       3.115  -0.507  -0.549  1.00  0.00
> N
> HETATM   28  C   NME     1       4.474  -1.010  -0.616  1.00  0.00
> C
> HETATM   29  H   NME     1       5.163  -0.381  -0.040  1.00  0.00
> H
> HETATM   30  H   NME     1       4.474  -2.015  -0.195  1.00  0.00
> H
> HETATM   31  H   NME     1       4.822  -1.054  -1.654  1.00  0.00
> H
> HETATM   32  H   NME     1       2.906   0.422  -0.885  1.00  0.00
> H
> CONECT    1    5    2   21
> CONECT    2    1    7    3    6
> CONECT    2
> CONECT    3   27    2    4
> CONECT    4    3
> CONECT    5    1
> CONECT    6    2
> CONECT    7   10    8    9    2
> CONECT    7
> CONECT    8   13    7   12
> CONECT    9    7
> CONECT   10    7
> CONECT   11   14   20   15
> CONECT   12    8   15   16
> CONECT   13   17   14    8
> CONECT   14   18   13   11
> CONECT   15   11   12   19
> CONECT   16   12
> CONECT   17   13
> CONECT   18   14
> CONECT   19   15
> CONECT   20   11
> CONECT   21   23    1   22
> CONECT   22   21
> CONECT   23   26   24   25   21
> CONECT   23
> CONECT   24   23
> CONECT   25   23
> CONECT   26   23
> CONECT   27   32   28    3
> CONECT   28   31   27   30   29
> CONECT   28
> CONECT   29   28
> CONECT   30   28
> CONECT   31   28
> CONECT   32   27
> MASTER        0    0    0    0    0    0    0    0   32    0   32    0
> END
>
>
>
> --
> View this message in context:
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> Sent from the GROMACS Users Forum mailing list archive at Nabble.com.
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