[gmx-users] Fatal error: In the chosen force field there is no residue type for 'GLN' as a starting terminus

Atila Petrosian atila.petrosian at gmail.com
Sun Nov 18 10:40:54 CET 2012


Dear David

Thanks for your attention.

I have 2 problems/questions:

1) There are a specific orientation for GLN ligand with regard to protein
in my system. If I do what you said [you make a separate molecule Gln-Ala
using pymol or vmd], specific orientation for GLN ligand with regard to
protein are changed.

2) topology obtained from NGLN-CALA is as follows:

[ moleculetype ]
; Name            nrexcl
Protein             3

[ atoms ]
;   nr       type  resnr residue  atom   cgnr     charge       mass
typeB    chargeB      massB
; residue   1 GLN rtp NGLN q +1.0
     1         N3      1    GLN      N      1     0.1493      14.01   ;
qtot 0.1493
     2          H      1    GLN     H1      2     0.1996      1.008   ;
qtot 0.3489
     3          H      1    GLN     H2      3     0.1996      1.008   ;
qtot 0.5485
     4          H      1    GLN     H3      4     0.1996      1.008   ;
qtot 0.7481
     5         CT      1    GLN     CA      5     0.0536      12.01   ;
qtot 0.8017
     6         HP      1    GLN     HA      6     0.1015      1.008   ;
qtot 0.9032
     7         CT      1    GLN     CB      7     0.0651      12.01   ;
qtot 0.9683
     8         HC      1    GLN    HB1      8      0.005      1.008   ;
qtot 0.9733
     9         HC      1    GLN    HB2      9      0.005      1.008   ;
qtot 0.9783
    10         CT      1    GLN     CG     10    -0.0903      12.01   ;
qtot 0.888
    11         HC      1    GLN    HG1     11     0.0331      1.008   ;
qtot 0.9211
    12         HC      1    GLN    HG2     12     0.0331      1.008   ;
qtot 0.9542
    13          C      1    GLN     CD     13     0.7354      12.01   ;
qtot 1.69
    14          O      1    GLN    OE1     14    -0.6133         16   ;
qtot 1.076
    15          N      1    GLN    NE2     15    -1.0031      14.01   ;
qtot 0.0732
    16          H      1    GLN   HE21     16     0.4429      1.008   ;
qtot 0.5161
    17          H      1    GLN   HE22     17     0.4429      1.008   ;
qtot 0.959
    18          C      1    GLN      C     18     0.6123      12.01   ;
qtot 1.571
    19          O      1    GLN      O     19    -0.5713         16   ;
qtot 1
; residue   2 ALA rtp CALA q -1.0
    20          N      2    ALA      N     20    -0.3821      14.01   ;
qtot 0.6179
    21          H      2    ALA      H     21     0.2681      1.008   ;
qtot 0.886
    22         CT      2    ALA     CA     22    -0.1747      12.01   ;
qtot 0.7113
    23         H1      2    ALA     HA     23     0.1067      1.008   ;
qtot 0.818
    24         CT      2    ALA     CB     24    -0.2093      12.01   ;
qtot 0.6087
    25         HC      2    ALA    HB1     25     0.0764      1.008   ;
qtot 0.6851
    26         HC      2    ALA    HB2     26     0.0764      1.008   ;
qtot 0.7615
    27         HC      2    ALA    HB3     27     0.0764      1.008   ;
qtot 0.8379
    28          C      2    ALA      C     28     0.7731      12.01   ;
qtot 1.611
    29         O2      2    ALA    OC1     29    -0.8055         16   ;
qtot 0.8055
    30         O2      2    ALA    OC2     30    -0.8055         16   ;
qtot 0


You said " Then you edit the top file (remove superfluous alanine atoms,
rename the N in ALA to O2 etc) with a text editor until it is "correct"
with help from the rtp file for CGLN. You may have to smooth the charges to
keep it neutral "

In ALA residue, all atoms except for N are redundant atoms. After removing
them and renaming N in ALA to O2, what remains in top file?
Both of NGLN and CALA or only NGLN?

If latter is true,

[ atoms ]
;   nr       type  resnr residue  atom   cgnr     charge       mass
typeB    chargeB      massB
; residue   1 GLN rtp GLN q  0.0
     1         N3      1    GLN      N      1     0.1493      14.01   ;
qtot 0.1493
     2          H      1    GLN     H1      2     0.1996      1.008   ;
qtot 0.3489
     3          H      1    GLN     H2      3     0.1996      1.008   ;
qtot 0.5485
     4          H      1    GLN     H3      4     0.1996      1.008   ;
qtot 0.7481
     5         CT      1    GLN     CA      5     0.0536      12.01   ;
qtot 0.8017
     6         HP      1    GLN     HA      6     0.1015      1.008   ;
qtot 0.9032
     7         CT      1    GLN     CB      7     0.0651      12.01   ;
qtot 0.9683
     8         HC      1    GLN    HB1      8      0.005      1.008   ;
qtot 0.9733
     9         HC      1    GLN    HB2      9      0.005      1.008   ;
qtot 0.9783
    10         CT      1    GLN     CG     10    -0.0903      12.01   ;
qtot 0.888
    11         HC      1    GLN    HG1     11     0.0331      1.008   ;
qtot 0.9211
    12         HC      1    GLN    HG2     12     0.0331      1.008   ;
qtot 0.9542
    13          C      1    GLN     CD     13     0.7354      12.01   ;
qtot 1.69
    14          O      1    GLN    OE1     14    -0.6133         16   ;
qtot 1.076
    15          N      1    GLN    NE2     15    -1.0031      14.01   ;
qtot 0.0732
    16          H      1    GLN   HE21     16     0.4429      1.008   ;
qtot 0.5161
    17          H      1    GLN   HE22     17     0.4429      1.008   ;
qtot 0.959
    18          C      1    GLN      C     18     0.6123      12.01   ;
qtot 1.571
    19         O2      2    GLN    OC1     19    -0.8055         16   ;
qtot 0.8055
    20         O2      2    GLN    OC2     20    -0.8055         16   ;
qtot 0


There is not such residue in rtp file (GLN with NH3+ and CO2- terminals)

Please guide me how to resolve this problem and obtain correct topology
file.



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