[gmx-users] Re: problems running grompp with protein-ligand complex

Ragnarok sdf fabracht1 at gmail.com
Tue Dec 2 13:33:30 CET 2008


Hello. I will try now to send part of my itp file and if another part
of the file is needed I will send it if requested.
Below are the emails that were already sent regarding my problem.
I hope I have not caused any incovenience.
Fabrício Bracht

" I am working with a protein-ligand complex in gromacs with ffamber99
forcefield. I was able to generate the topology file for my ligand
with acpypi. Was also able to insert the ligand coordinates into my
protein's coordinate file. Was also able to generate the water box
with genbox. The number of molecules all match, the ligand coordinates
are still there but grompp tells me that:
Fatal error: Found a second defaults directive, file "ligand.itp", line 5
I've checked wikigromacs, but the solution given there, to simply
erase the second default line does not suit me here. Once I do this, i
mean, go to my ligand.itp file and put a ; before my default section,
grompp does not recognize anymore that my ligand is there and gives
out another error line.
I would like some advice on the matter if possible.
Thank you in advance
Fabrício Bracht

>Well, it's not like grompp is recognizing you have a ligand there
>right now, is it? grompp doesn't reach the point where it realizes you
>don't seem to have a ligand. It seems there's something wrong with the
>topology. Better post ligand.itp, like Justin suggests, and also give
>the error which occurs when you do comment out the defaults line in
>the ligand topology.
>
>Cheers,
>
>Tsjerk "

Now, the actual itp file.

; M_E.top created by acpypi on Wed Nov 26 18:00:37 2008

[ defaults ]
; nbfunc        comb-rule       gen-pairs       fudgeLJ fudgeQQ
1               2               yes             0.5     0.8333

[ atomtypes ]
;name   bond_type     mass     charge   ptype   sigma         epsilon       Amb
 o        o           0.00000  0.00000   A     2.95992e-01
8.78640e-01 ; 1.66  0.2100
 c        c           0.00000  0.00000   A     3.39967e-01
3.59824e-01 ; 1.91  0.0860
 oh       oh          0.00000  0.00000   A     3.06647e-01
8.80314e-01 ; 1.72  0.2104
 ho       ho          0.00000  0.00000   A     0.00000e+00
0.00000e+00 ; 0.00  0.0000
 c3       c3          0.00000  0.00000   A     3.39967e-01
4.57730e-01 ; 1.91  0.1094
 hc       hc          0.00000  0.00000   A     2.64953e-01
6.56888e-02 ; 1.49  0.0157
 c2       c2          0.00000  0.00000   A     3.39967e-01
3.59824e-01 ; 1.91  0.0860
 ha       ha          0.00000  0.00000   A     2.59964e-01
6.27600e-02 ; 1.46  0.0150
 ce       ce          0.00000  0.00000   A     3.39967e-01
3.59824e-01 ; 1.91  0.0860
 cf       cf          0.00000  0.00000   A     3.39967e-01
3.59824e-01 ; 1.91  0.0860

[ moleculetype ]
;name            nrexcl
 M_E              3

[ atoms ]
;   nr  type  resi  res  atom  cgnr     charge      mass       typeB    chargeB
     1    o     1    M_E   O49    1     -0.55230     16.00000 ; qtot -0.552
     2    c     1    M_E   C48    2      0.63200     12.01000 ; qtot 0.080
     3   oh     1    M_E   O50    3     -0.60900     16.00000 ; qtot -0.529
     4   ho     1    M_E   H51    4      0.44690      1.00800 ; qtot -0.082
     5   c3     1    M_E   C45    5     -0.12590     12.01000 ; qtot -0.208
     6   hc     1    M_E   H46    6      0.08080      1.00800 ; qtot -0.127
     7   hc     1    M_E   H47    7      0.08110      1.00800 ; qtot -0.046
     8   c3     1    M_E   C42    8     -0.07210     12.01000 ; qtot -0.118
     9   hc     1    M_E   H43    9      0.06640      1.00800 ; qtot -0.052
    10   hc     1    M_E   H44   10      0.05040      1.00800 ; qtot -0.002
    11   c3     1    M_E   C39   11     -0.05170     12.01000 ; qtot -0.053
    12   hc     1    M_E   H40   12      0.04490      1.00800 ; qtot -0.008
    13   hc     1    M_E   H41   13      0.05410      1.00800 ; qtot 0.046
    14   c2     1    M_E   C37   14     -0.16730     12.01000 ; qtot -0.122
    15   ha     1    M_E   H38   15      0.11950      1.00800 ; qtot -0.002
    16   c2     1    M_E   C35   16     -0.16710     12.01000 ; qtot -0.169
    17   ha     1    M_E   H36   17      0.11730      1.00800 ; qtot -0.052
    18   c3     1    M_E   C32   18     -0.04940     12.01000 ; qtot -0.101
    19   hc     1    M_E   H33   19      0.07250      1.00800 ; qtot -0.029
    20   hc     1    M_E   H34   20      0.06180      1.00800 ; qtot 0.033
    21   c3     1    M_E    C2   21     -0.00340     12.01000 ; qtot 0.030
    22   hc     1    M_E    H6   22      0.07250      1.00800 ; qtot 0.102
    23   c2     1    M_E    C1   23     -0.10390     12.01000 ; qtot -0.002
    24   ha     1    M_E    H8   24      0.14850      1.00800 ; qtot 0.147
    25   ce     1    M_E    C5   25     -0.25360     12.01000 ; qtot -0.107
    26   ha     1    M_E    H9   26      0.16130      1.00800 ; qtot 0.054
    27    c     1    M_E    C4   27      0.56070     12.01000 ; qtot 0.615
    28    o     1    M_E    O7   28     -0.52650     16.00000 ; qtot 0.089
    29   ce     1    M_E    C3   29     -0.21970     12.01000 ; qtot -0.131
    30   cf     1    M_E   C10   30     -0.04110     12.01000 ; qtot -0.172
    31   ha     1    M_E   H11   31      0.14510      1.00800 ; qtot -0.027
    32   cf     1    M_E   C12   32     -0.16880     12.01000 ; qtot -0.196
    33   ha     1    M_E   H13   33      0.12600      1.00800 ; qtot -0.070
    34   c2     1    M_E   C14   34     -0.12090     12.01000 ; qtot -0.191
    35   ha     1    M_E   H15   35      0.12220      1.00800 ; qtot -0.069
    36   c3     1    M_E   C16   36     -0.06070     12.01000 ; qtot -0.129
    37   hc     1    M_E   H17   37      0.05610      1.00800 ; qtot -0.073
    38   hc     1    M_E   H18   38      0.05520      1.00800 ; qtot -0.018
    39   c3     1    M_E   C19   39     -0.07610     12.01000 ; qtot -0.094
    40   hc     1    M_E   H20   40      0.04810      1.00800 ; qtot -0.046
    41   hc     1    M_E   H21   41      0.03740      1.00800 ; qtot -0.009
    42   c3     1    M_E   C22   42     -0.07850     12.01000 ; qtot -0.087
    43   hc     1    M_E   H23   43      0.04140      1.00800 ; qtot -0.046
    44   hc     1    M_E   H24   44      0.03920      1.00800 ; qtot -0.007
    45   c3     1    M_E   C25   45     -0.08090     12.01000 ; qtot -0.088
    46   hc     1    M_E   H26   46      0.03910      1.00800 ; qtot -0.048
    47   hc     1    M_E   H27   47      0.04220      1.00800 ; qtot -0.006
    48   c3     1    M_E   C28   48     -0.09280     12.01000 ; qtot -0.099
    49   hc     1    M_E   H29   49      0.03180      1.00800 ; qtot -0.067
    50   hc     1    M_E   H30   50      0.03440      1.00800 ; qtot -0.033
    51   hc     1    M_E   H31   51      0.03280      1.00800 ; qtot -0.000

[ bonds ]
;   ai     aj funct   r             k
     3      4   1    9.7400e-02    3.0928e+05 ;    O50 - H51
(more text not sent)
[ pairs ]
;   ai     aj    funct
     6      9      1 ;    H46 - H43
(more text not sent)

[ angles ]
;   ai     aj     ak    funct   theta         cth
     2      3      4      1    1.0737e+02    4.2844e+02 ;    C48 - O50
   - H51
(more text not sent)

[ dihedrals ] ; propers
; treated as RBs in GROMACS to use combine multiple AMBER torsions per quartet
; i   j   k   l func   C0        C1        C2        C3        C4        C5
  1   2   3   4   3   27.19600   -7.94960  -19.24640    0.00000
0.00000    0.00000 ;    O49-   C48-   O50-   H51
(more text not sent)

[ dihedrals ] ; impropers
; treated as propers in GROMACS to use correct AMBER analytical function
; i   j   k   l func  phase     kd      pn
 16  11  14  15   1   180.00   4.60240   2 ;    C35-   C39-   C37-   H38
(more text not sent)

[ system ]
 M_E

[ molecules ]
; Compound        nmols
 M_E              1



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