[gmx-users] first residue in chains warning issue

Ming Tang m21.tang at qut.edu.au
Tue May 12 00:48:20 CEST 2015


Hi Justin,

Here is the output of pdb2gmx:

Command line:
  pdb2gmx -f hyp_lys.pdb -o complex.gro -ignh -ter -ff gromos54a7 -water SPC


Using the Gromos54a7 force field in directory gromos54a7.ff

Opening force field file /usr/local/gromacs/share/gromacs/top/gromos54a7.ff/aminoacids.r2b
Reading hyp_lys.pdb...
Read 20130 atoms
Analyzing pdb file
Splitting chemical chains based on TER records or chain id changing.
There are 3 chains and 0 blocks of water and 3134 residues with 20130 atoms

  chain  #res #atoms
  1 'A'  1054   6788  
  2 'B'  1026   6554  
  3 'C'  1054   6788  

All occupancies are one
Opening force field file /usr/local/gromacs/share/gromacs/top/gromos54a7.ff/atomtypes.atp
Atomtype 58
Reading residue database... (gromos54a7)
Opening force field file /usr/local/gromacs/share/gromacs/top/gromos54a7.ff/aminoacids.rtp
Using default: not generating all possible dihedrals
Using default: excluding 3 bonded neighbors
Using default: generating 1,4 H--H interactions
Using default: removing proper dihedrals found on the same bond as a proper dihedral
Residue 108
Sorting it all out...
Opening force field file /usr/local/gromacs/share/gromacs/top/gromos54a7.ff/aminoacids.hdb
Opening force field file /usr/local/gromacs/share/gromacs/top/gromos54a7.ff/aminoacids.n.tdb
Opening force field file /usr/local/gromacs/share/gromacs/top/gromos54a7.ff/aminoacids.c.tdb

Back Off! I just backed up topol.top to ./#topol.top.2#
Processing chain 1 'A' (6788 atoms, 1054 residues)
Analysing hydrogen-bonding network for automated assignment of histidine
 protonation. 1365 donors and 1444 acceptors were found.
There are 1748 hydrogen bonds
Will use HISE for residue 105
Will use HISE for residue 948
Identified residue GLN1 as a starting terminus.
Identified residue TYR1054 as a ending terminus.
8 out of 8 lines of specbond.dat converted successfully
Special Atom Distance matrix:
                    MET2   MET19   MET55  MET102  HIS105  MET139  MET418
                    SD15   SD136   SD369   SD678  NE2702   SD926  SD2692
   MET19   SD136   5.356
   MET55   SD369  16.259  10.913
  MET102   SD678  29.737  24.390  13.588
  HIS105  NE2702  30.104  24.755  13.935   0.427
  MET139   SD926  40.534  35.194  24.356  10.855  10.499
  MET418  SD2692 121.526 116.225 105.475  91.946  91.605  81.150
  MET567  SD3648 163.789 158.490 147.754 134.205 133.865 123.429  42.327
  MET838  SD5366 241.858 236.550 225.799 212.233 211.888 201.460 120.429
  HIS948 NE26069 273.040 267.735 256.991 243.424 243.081 232.655 151.608
                  MET567  MET838
                  SD3648  SD5366
  MET838  SD5366  78.135
  HIS948 NE26069 109.299  31.201
Select start terminus type for GLN-1
 0: NH3+
 1: NH2
 2: None
1
Start terminus GLN-1: NH2
Select end terminus type for TYR-1054
 0: COO-
 1: COOH
 2: None
1
End terminus TYR-1054: COOH
Checking for duplicate atoms....
Generating any missing hydrogen atoms and/or adding termini.
Now there are 1054 residues with 8346 atoms
Chain time...

Back Off! I just backed up topol_Protein_chain_A.itp to ./#topol_Protein_chain_A.itp.2#
Making bonds...
Number of bonds was 8606, now 8602
Generating angles, dihedrals and pairs...

WARNING: WARNING: Residue 1 named GLN of a molecule in the input file was mapped
to an entry in the topology database, but the atom H used in
an interaction of type angle in that entry is not found in the
input file. Perhaps your atom and/or residue naming needs to be
fixed.


Before cleaning: 14519 pairs
Before cleaning: 16187 dihedrals
Making cmap torsions...
There are 5421 dihedrals, 3614 impropers, 12466 angles
          14519 pairs,     8602 bonds and     0 virtual sites
Total mass 96375.038 a.m.u.
Total charge 8.000 e
Writing topology

Back Off! I just backed up posre_Protein_chain_A.itp to ./#posre_Protein_chain_A.itp.2#
Processing chain 2 'B' (6554 atoms, 1026 residues)


I checked the output complex.gro and topol_Protein_Chain_A.itp,  and found that the first GLN has only one H atom more than other GLN, which I think is correct.

   1GLN      N    1  -1.055   1.642  -0.003
    1GLN     H1    2  -1.105   1.722  -0.036
    1GLN     H2    3  -0.979   1.623  -0.064
    1GLN     CA    4  -1.008   1.667   0.124
    1GLN     CB    5  -1.122   1.705   0.221
    1GLN     CG    6  -1.078   1.745   0.361
    1GLN     CD    7  -1.194   1.789   0.448
    1GLN    OE1    8  -1.309   1.791   0.404
    1GLN    NE2    9  -1.164   1.827   0.572
    1GLN   HE21   10  -1.069   1.824   0.603
    1GLN   HE22   11  -1.237   1.857   0.634
    1GLN      C      12  -0.930   1.549   0.184
    1GLN      O     13  -0.964   1.434   0.161

   40GLN      N  334   0.845   1.381  11.647
   40GLN      H  335   0.761   1.434  11.633
   40GLN     CA  336   0.932   1.413  11.759
   40GLN     CB  337   0.862   1.510  11.855
   40GLN     CG  338   0.950   1.559  11.969
   40GLN     CD  339   0.879   1.660  12.057
   40GLN    OE1  340   0.759   1.684  12.043
   40GLN    NE2  341   0.953   1.720  12.150
   40GLN   HE21  342   1.051   1.697  12.158
   40GLN   HE22  343   0.912   1.787  12.211
   40GLN      C  344   0.979   1.290  11.834
   40GLN      O  345   0.897   1.214  11.885

; residue   1 GLN rtp GLN  q  0.0
     1         NL      1    GLN      N      1      -0.66    14.0067   ; qtot -0.66
     2          H      1    GLN     H1      1       0.44      1.008   ; qtot -0.22
     3          H      1    GLN     H2      1       0.44      1.008   ; qtot 0.22
     4        CH1      1    GLN     CA      2      -0.22     13.019   ; qtot 0
     5        CH2      1    GLN     CB      2          0     14.027   ; qtot 0
     6        CH2      1    GLN     CG      2          0     14.027   ; qtot 0
     7          C      1    GLN     CD      3       0.29     12.011   ; qtot 0.29
     8          O      1    GLN    OE1      3      -0.45    15.9994   ; qtot -0.16
     9         NT      1    GLN    NE2      3      -0.72    14.0067   ; qtot -0.88
    10          H      1    GLN   HE21      3       0.44      1.008   ; qtot -0.44
    11          H      1    GLN   HE22      3       0.44      1.008   ; qtot 0
    12          C      1    GLN      C      4       0.45     12.011   ; qtot 0.45
    13          O      1    GLN      O      4      -0.45    15.9994   ; qtot 0

; residue  40 GLN rtp GLN  q  0.0
   334          N     40    GLN      N    159      -0.31    14.0067   ; qtot -0.31
   335          H     40    GLN      H    159       0.31      1.008   ; qtot 0
   336        CH1     40    GLN     CA    160          0     13.019   ; qtot 0
   337        CH2     40    GLN     CB    160          0     14.027   ; qtot 0
   338        CH2     40    GLN     CG    160          0     14.027   ; qtot 0
   339          C     40    GLN     CD    161       0.29     12.011   ; qtot 0.29
   340          O     40    GLN    OE1    161      -0.45    15.9994   ; qtot -0.16
   341         NT     40    GLN    NE2    161      -0.72    14.0067   ; qtot -0.88
   342          H     40    GLN   HE21    161       0.44      1.008   ; qtot -0.44
   343          H     40    GLN   HE22    161       0.44      1.008   ; qtot 0
   344          C     40    GLN      C    162       0.45     12.011   ; qtot 0.45
   345          O     40    GLN      O    162      -0.45    15.9994   ; qtot 0

But it does not give any warnings about the last residue of the three chains.  Is there anything wrong with this .itp?
Thanks a lot.

-----Original Message-----
From: gromacs.org_gmx-users-bounces at maillist.sys.kth.se [mailto:gromacs.org_gmx-users-bounces at maillist.sys.kth.se] On Behalf Of Justin Lemkul
Sent: Monday, 11 May 2015 9:44 PM
To: gmx-users at gromacs.org
Subject: Re: [gmx-users] first residue in chains warning issue



On 5/10/15 11:36 PM, Ming Tang wrote:
> Dear all,
>
> I built a triple helix with 2 GLN and 1 SER being the first residue of the three chains. However, while using pdb2gmx -f 1.pdb -o complex.gro -ignh -ter -ff gromos54a7 -water SPC and choosing NH2 or NH3+ as the start terminus type for GLN-1  and SER-1, I came across the following warnings:
>
> WARNING: WARNING: Residue 1 named GLN (SER) of a molecule in the input 
> file was mapped to an entry in the topology database, but the atom H used in an interaction of type angle in that entry is not found in the input file. Perhaps your atom and/or residue naming needs to be fixed.
>

You'll need to provide the full screen output from pdb2gmx; this shouldn't happen if all the selections are made correctly and chain termini are identified as they should be.

> Then, I checked the .pdb and .rtp files. The difference between GLN-1/SER-1 and GLN-n/SER-n (n>1) is that GLN-1/SER-1 contains 2 more H atoms.
>

Because you're providing a fully protonated N-terminus (which is fine) with non-unique atom names (which pdb2gmx will take care of when using -ignh).

> Residue GLN-1 in .pdb
> ATOM      1  N   GLN A   1     -10.554  16.421  -0.030  1.00  0.00           N1+
> ATOM      2  CA  GLN A   1     -10.080  16.667   1.238  1.00  0.00           C
> ATOM      3  C   GLN A   1      -9.305  15.495   1.835  1.00  0.00           C
> ATOM      4  O   GLN A   1      -9.636  14.335   1.608  1.00  0.00           O
> ATOM      5  CB  GLN A   1     -11.222  17.053   2.210  1.00  0.00           C
> ATOM      6  CD  GLN A   1     -11.943  17.895   4.480  1.00  0.00           C
> ATOM      7  NE2 GLN A   1     -11.643  18.268   5.719  1.00  0.00           N
> ATOM      8  OE1 GLN A   1     -13.093  17.905   4.041  1.00  0.00           O
> ATOM      9  CG  GLN A   1     -10.784  17.445   3.612  1.00  0.00           C
> ATOM     10  HE2 GLN A   1     -12.366  18.573   6.339  1.00  0.00           H
> ATOM     11  HE2 GLN A   1     -10.694  18.243   6.032  1.00  0.00           H
> ATOM     12  H   GLN A   1     -11.086  17.245  -0.422  1.00  0.00           H
> ATOM     13  H   GLN A   1      -9.773  16.207  -0.708  1.00  0.00           H
> ATOM     14  H   GLN A   1     -11.212  15.593  -0.048  1.00  0.00           H
>
> Parameters in .rtp in gromos54a7
> [ GLN ]
> [ atoms ]
>      N     N    -0.31000     0
>      H     H     0.31000     0
>     CA   CH1     0.00000     1
>     CB   CH2     0.00000     1
>     CG   CH2     0.00000     1
>     CD     C     0.29000     2
>   OE1     O    -0.45000     2
>    NE2    NT    -0.72000     2
> HE21     H     0.44000     2
> HE22     H     0.44000     2
>      C     C       0.450     3
>      O     O      -0.450     3
> [ angles ]
> ;  ai    aj    ak   gromos type
>     -C     N     H     ga_32
>     -C     N    CA     ga_31
>      H     N    CA     ga_18
>      N    CA    CB     ga_13
>      N    CA     C     ga_13
>     CB    CA     C     ga_13
>     CA    CB    CG     ga_15
>     CB    CG    CD     ga_15
>     CG    CD   OE1     ga_30
>     CG    CD   NE2     ga_19
>    OE1    CD   NE2     ga_33
>     CD   NE2  HE21     ga_23
>     CD   NE2  HE22     ga_23
>   HE21   NE2  HE22     ga_24
>     CA     C     O     ga_30
>     CA     C    +N     ga_19
> O     C    +N     ga_33
>
> Further, I compared atoms of GLN in .pdb and .rtp, and changed 2 HE into HE21 and HE22, but got the same warnings.
>

You're using -ignh, so all H atoms are ignored per your instruction.

> The simulation can be move forward to EM and NPT smoothly. Does this kind of warning affect the simulation results significantly?
>

If the topology winds up being sane, then it's fine, but warnings from pdb2gmx are usually weird in the case of normal topologies.  Inspect the termini.

-Justin

--
==================================================

Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441 http://mackerell.umaryland.edu/~jalemkul

==================================================
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