[gmx-users] Re: help with "interaction of type atom in the topology"...

Mark Abraham Mark.Abraham at anu.edu.au
Fri Aug 31 05:37:41 CEST 2012


On 31/08/2012 1:03 PM, klexa wrote:
>  >>
>
> If I recall correctly, the residue number printed by pdb2gmx is 
> actually the
> residue index (starting from zero), so the problematic residue is MLE, 
> which
> does have CB.

Good thought, but the index here starts counting from 1 (and has done so 
for at least as far back as 4.5.5), so it really means residue 7.

>
> -Justin
>
>
>>>
>
> Hi Justin,
>
> Thank you for the fast response. That makes sense, but the problematic 
> residue is actually both I guess - I tried just a trimer of 
> ALA-SAR-ALA, and it chokes, it also fails with the same error for the 
> trimer of ALA-MLE-ALA, while a different nonstandard amino acid that I 
> made succeeds as a trimer ALA-ABA-ALA - the major difference perhaps 
> being the fact that the peptide bond N is methylated for MLE and SAR 
> but not for ABA that suceeds? This is what MLE looks like:
>
>
> [ MLE ]
>  [ atoms ]
>      N    N           -0.22670     1
>     CN    CT          -0.22340     2
>    HN1    H            0.10210     3
>    HN2    H            0.10210     4
>    HN3    H            0.10210     5
>     CA    CT          -0.05180     6
>     HA    H1           0.09220     7
>     CB    CT          -0.11020     8
>    HB2    HC           0.04570     9
>    HB3    HC           0.04570    10
>     CG    CT           0.35310    11
>     HG    HC          -0.03610    12
>    CD1    CT          -0.41210    13
>   HD11    HC           0.10000    14
>   HD12    HC           0.10000    15
>   HD13    HC           0.10000    16
>    CD2    CT          -0.41210    17
>   HD21    HC           0.10000    18
>   HD22    HC           0.10000    19
>   HD23    HC           0.10000    20
>      C    C            0.59730    21
>      O    O           -0.56790    22
>  [ bonds ]
>      N    CN
>     CN   HN1
>     CN   HN2
>     CN   HN3
>      N    CA
>     CA    HA
>     CA    CB
>     CA     C
>     CB   HB2
>     CB   HB3
>     CB    CG
>     CG    HG
>     CG   CD1
>     CG   CD2
>    CD1  HD11
>    CD1  HD12
>    CD1  HD13
>    CD2  HD21
>    CD2  HD22
>    CD2  HD23
>      C     O
>     -C     N
>  [ impropers ]
>     -C    CA     N    CN
>     CA    +N     C     O
>
>
> MODEL        1
> ATOM      1  N   ALA A   1     2.847   5.798  -7.887  1.00 0.00         N
> ATOM      2  CA  ALA A   1     1.622   5.058  -8.157  1.00 0.00         C
> ATOM      3  C   ALA A   1     1.902   3.942  -9.176  1.00 0.00         C
> ATOM      4  O   ALA A   1     3.029   3.773  -9.643  1.00 0.00         O
> ATOM      5  CB  ALA A   1     0.549   6.042  -8.629  1.00 0.00         C
> ATOM      6  H   ALA A   1     3.680   5.502  -8.376  1.00 0.00         H
> ATOM      7  HA  ALA A   1     1.214   4.676  -7.221  1.00 0.00         H
> ATOM      8  HB1 ALA A   1    -0.375   5.501  -8.835  1.00 0.00         H
> ATOM      9  HB2 ALA A   1     0.369   6.785  -7.852  1.00 0.00         H
> ATOM     10  HB3 ALA A   1     0.887   6.541  -9.537  1.00 0.00         H
> ATOM     11  N   MLE A   2     0.814   3.165  -9.517  1.00 0.00         N
> ATOM     12  CN  MLE A   2     0.967   2.072 -10.481  1.00 0.00         C
> ATOM     13  CA  MLE A   2    -0.491   3.432  -8.917  1.00 0.00         C
> ATOM     14  C   MLE A   2    -0.439   3.310  -7.362  1.00 0.00         C
> ATOM     15  O   MLE A   2     0.107   2.398  -6.778  1.00 0.00         O
> ATOM     16  CB  MLE A   2    -1.599   2.488  -9.538  1.00 0.00         C
> ATOM     17  CG  MLE A   2    -2.739   3.173 -10.337  1.00 0.00         C
> ATOM     18  CD1 MLE A   2    -3.758   3.767  -9.396  1.00 0.00         C
> ATOM     19  CD2 MLE A   2    -2.404   4.282 -11.348  1.00 0.00         C
> ATOM     20  HN1 MLE A   2     1.313   2.473 -11.433  1.00 0.00         H
> ATOM     21  HN2 MLE A   2     1.696   1.354 -10.103  1.00 0.00         H
> ATOM     22  HN3 MLE A   2     0.008   1.575 -10.623  1.00 0.00         H
> ATOM     23  HA  MLE A   2    -0.732   4.490  -9.025  1.00 0.00         H
> ATOM     24  HB2 MLE A   2    -1.134   1.789 -10.233  1.00 0.00         H
> ATOM     25  HB3 MLE A   2    -2.093   1.933  -8.740  1.00 0.00         H
> ATOM     26  HG  MLE A   2    -3.192   2.451 -11.016  1.00 0.00         H
> ATOM     27 HD11 MLE A   2    -4.551   4.244  -9.972  1.00 0.00         H
> ATOM     28 HD12 MLE A   2    -4.184   2.978  -8.776  1.00 0.00         H
> ATOM     29 HD13 MLE A   2    -3.276   4.509  -8.759  1.00 0.00         H
> ATOM     30 HD21 MLE A   2    -3.323   4.643 -11.810  1.00 0.00         H
> ATOM     31 HD22 MLE A   2    -1.909   5.106 -10.834  1.00 0.00         H
> ATOM     32 HD23 MLE A   2    -1.742   3.885 -12.118  1.00 0.00         H
> ATOM     33  N   ALA A   3    -1.059   4.314  -6.647  1.00 0.00         N
> ATOM     34  CA  ALA A   3    -1.097   4.341  -5.192  1.00 0.00         C
> ATOM     35  C   ALA A   3      -1.861   5.587  -4.715  1.00 
> 0.00           C
> ATOM     36  O   ALA A   3      -2.338   6.389  -5.518  1.00 
> 0.00           O
> ATOM     37  CB  ALA A   3       0.338   4.283  -4.663  1.00 
> 0.00           C
> ATOM     38  H   ALA A   3      -1.514   5.074  -7.133  1.00 
> 0.00           H
> ATOM     39  HA  ALA A   3      -1.536   3.415  -4.821  1.00 
> 0.00           H
> ATOM     40  HB1 ALA A   3       0.325   4.303  -3.573  1.00 
> 0.00           H
> ATOM     41  HB2 ALA A   3       0.815   3.364  -5.003  1.00 
> 0.00           H
> ATOM     42  HB3 ALA A   3       0.898   5.141  -5.034  1.00 
> 0.00           H
> TER      43      ALA A   3

I think the critical difference here is that you may not be building 
hydrogens for MLE in this structure, whereas you were in the SAR example 
earlier. Giving your pdb2gmx command lines would perhaps have made 
things easier to understand w.r.t. use of -ignh or not. pdb2gmx is 
failing at a point consistent with the timing of hydrogen building, but 
perhaps I might patch it to be more explicit about that. I'm expecting 
that your .hdb entries for some of these new residues refer to CB and 
this generates the error. Using pdb2gmx -debug 1, or trying the above 
example with -ignh may prove illuminating, also.

Mark



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