[gmx-users] Problem with simulation of Protein-DNA complex

rarora at ens-cachan.fr rarora at ens-cachan.fr
Thu Feb 9 13:44:26 CET 2012


Dear Gromacs users,

I have been trying to simulate a Protein-DNA complex using gromacs,  
but each time I have been facing problems. I would like to point out  
that both the Protein and DNA have been modeled and after that docked  
in order to obtain a complex. Following are the parameters I am using:

Force-Field: amber99sb-ildn
water model: TIP3P

40 NA ions were added in order to neutralise the complex-solvent  
system. Gromacs doesn't show any error up until I proceed to do nvt  
equilibriation. Following is nvt.mdp:

title           = PFV_DNA_NVT
define          = -DPOSRES      ; position restrain the protein
; Run parameters
integrator      = md            ; leap-frog integrator
nsteps          = 1000000       ; 2 * 50000 = 100 ps
dt              = 0.001         ; 2 fs
; Output control
nstxout         = 100           ; save coordinates every 0.2 ps
nstvout         = 100           ; save velocities every 0.2 ps
nstenergy       = 100           ; save energies every 0.2 ps
nstlog          = 100           ; update log file every 0.2 ps
; Bond parameters
continuation    = no            ; first dynamics run
constraint_algorithm = lincs    ; holonomic constraints
constraints     = all-bonds     ; all bonds (even heavy atom-H bonds)  
constrained
lincs_iter      = 1             ; accuracy of LINCS
lincs_order     = 4             ; also related to accuracyi
; Neighborsearching
ns_type         = grid          ; search neighboring grid cels
nstlist         = 5             ; 10 fs
rlist           = 1.0           ; short-range neighborlist cutoff (in nm)
rcoulomb        = 1.0           ; short-range electrostatic cutoff (in nm)
rvdw            = 1.0           ; short-range van der Waals cutoff (in nm)
; Electrostatics
coulombtype     = PME           ; Particle Mesh Ewald for long-range  
electrostatics
pme_order       = 4             ; cubic interpolation
fourierspacing  = 0.16          ; grid spacing for FFT
; Temperature coupling is on
tcoupl          = V-rescale     ; modified Berendsen thermostat
tc-grps         = Protein Non-Protein
tau_t           = 0.1   0.1     ; time constant, in ps
ref_t           = 300   300     ; reference temperature, one for each  
group, in K
; Pressure coupling is off
pcoupl          = no            ; no pressure coupling in NVT
; Periodic boundary conditions
pbc             = xyz           ; 3-D PBC
; Dispersion correction
DispCorr        = EnerPres      ; account for cut-off vdW scheme
; Velocity generation
gen_vel         = yes           ; assign velocities from Maxwell distribution
gen_temp        = 300           ; temperature for Maxwell distribution
gen_seed        = -1            ; generate a random seed


It generates a tpr, but upon mpirun gives the following error:

starting mdrun 'Protein in water'
1000000 steps,   1000.0 ps.

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.027514, max 0.979682 (between atoms 3460 and 3461)
bonds that rotated more than 30 degrees:
  atom 1 atom 2  angle  previous, current, constraint length
    3455   3457   65.2    0.1542   0.2535      0.1526
    3455   3456   33.3    0.1093   0.1322      0.1090
    3457   3459   72.7    0.1105   0.1739      0.1090
    3457   3458   65.7    0.1105   0.1588      0.1090
    3460   3469   78.6    0.1409   0.2693      0.1400
    3460   3461   78.8    0.1409   0.2772      0.1400
    3461   3463   75.1    0.1406   0.1489      0.1400
    3463   3465   37.2    0.1403   0.1756      0.1400
    3463   3464   40.7    0.1083   0.1408      0.1080
    3465   3467   35.5    0.1403   0.1733      0.1400
    3467   3469   74.0    0.1405   0.1373      0.1400
    3467   3468   42.9    0.1083   0.1433      0.1080
Wrote pdb files with previous and current coordinates

Step 1, time 0.001 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 364940.065742, max 11977066.000000 (between atoms 3465 and 3466)
bonds that rotated more than 30 degrees:
  atom 1 atom 2  angle  previous, current, constraint length
    3475   3495  110.8    0.1526 20544.7148      0.1522
    3475   3477  111.6    0.1529 20544.4336      0.1526
    3475   3476  108.1    0.1094 20543.1309      0.1090
    3477   3480   62.8    0.1527   4.6441      0.1526
    3477   3479   57.5    0.1091   4.5683      0.1090
    3477   3478   93.6    0.1091   4.6160      0.1090
    3495   3497  138.1    0.1336   4.9133      0.1335
    3495   3496   69.6    0.1230   4.9085      0.1229
    3497   3499   40.2    0.1449   0.2036      0.1449
    3497   3498   43.8    0.1010   0.1527      0.1010
    3480   3483   35.6    0.1526   0.1902      0.1526
    3480   3482   42.2    0.1090   0.1501      0.1090
    3480   3481   41.7    0.1090   0.1485      0.1090
    3453   3455   88.7    0.1701 117322.3672      0.1449
    3453   3454   88.3    0.1035 65066.2227      0.1010
    3455   3471   48.9    0.1763 171383.6562      0.1522
    3455   3457  134.6    0.2535 572521.2500      0.1526
    3455   3456   66.7    0.1322 143042.0000      0.1090
    3457   3460   67.5    0.1678 877653.8125      0.1510
    3457   3459  126.5    0.1739 558348.5625      0.1090
    3457   3458  124.8    0.1588 590731.2500      0.1090
    3460   3469   76.0    0.2693 1002008.1250      0.1400
    3460   3461   72.0    0.2772 1000899.3125      0.1400
    3469   3470  158.0    0.1043 269832.5938      0.1080
    3471   3473  128.5    0.1397 181301.0469      0.1335
    3471   3472  107.1    0.1287 184187.9531      0.1229
    3473   3475   71.3    0.1467 25968.8105      0.1449
    3473   3474   95.3    0.1028 20024.4492      0.1010
    3439   3441   69.6    0.1452 7261.8906      0.1449
    3439   3440   61.1    0.1011   3.6659      0.1010
    3441   3451   75.5    0.1533 16031.6553      0.1522
    3441   3443   69.0    0.1529 7261.8286      0.1526
    3441   3442   71.2    0.1092 7260.9429      0.1090
    3443   3446   67.8    0.1523   4.1676      0.1522
    3443   3445   70.1    0.1090   4.1174      0.1090
    3443   3444   69.3    0.1090   4.1167      0.1090
    3451   3453   30.1    0.1366 48307.3984      0.1335
    3451   3452   76.4    0.1240 17451.3633      0.1229
   10016  10015   71.1    0.1410   5.2172      0.1410
   10017  10016   34.0    0.1090   0.1348      0.1090
   10036  10034   43.0    0.1090   0.1529      0.1090
   10035  10034   42.4    0.1090   0.1512      0.1090
    3461   3463   62.2    0.1489 549183.7500      0.1400
    3461   3462  161.0    0.1064 307931.5938      0.1080
    3463   3465   99.9    0.1756 1277050.1250      0.1400
    3463   3464  116.4    0.1408 217171.0469      0.1080
    3465   3467   99.6    0.1733 1273120.5000      0.1400
    3465   3466   79.3    0.1113 1293523.2500      0.1080
    3467   3469   62.5    0.1373 506361.1875      0.1400
    3467   3468  123.9    0.1433 186052.9531      0.1080
   10006  10005  118.8    0.1607 166.0911      0.1610
   10009  10006  107.1    0.1605 208.0792      0.1610
   10008  10006   93.6    0.1475 253.8065      0.1480
   10007  10006   89.6    0.1486 1342.3563      0.1480
   10010  10009   79.7    0.1420 156.5771      0.1410
   10013  10010  121.4    0.1526 101.7273      0.1526
   10012  10010  102.0    0.1091 109.8340      0.1090
   10011  10010  105.1    0.1090 109.8889      0.1090
   10032  10013   65.8    0.1528  21.9936      0.1526
   10015  10013   91.8    0.1411  20.4329      0.1410
   10014  10013  134.6    0.1092   5.6451      0.1090
   10037  10032   34.2    0.1410   5.9761      0.1410
   10034  10032   81.2    0.1526   5.9242      0.1526
   10033  10032  106.9    0.1090   5.9566      0.1090
    3446   3447   30.2    0.1229   0.1508      0.1229
    3437   3439   57.6    0.1336   3.7366      0.1335
    3437   3438   32.2    0.1229   0.1564      0.1229
    9980   9979  133.8    0.1410   5.2959      0.1410
    9986   9985  133.0    0.1410   3.7189      0.1410
   10002   9986   71.7    0.1527  15.9062      0.1526
    9988   9986  115.7    0.1475   2.9843      0.1475
    9987   9986  105.0    0.1090   3.0316      0.1090
    9989   9988   32.0    0.1365   0.1736      0.1365
   10004  10002   82.7    0.1091  13.0663      0.1090
   10003  10002  108.3    0.1092   8.0967      0.1090
    9983   9980   60.5    0.1529  23.4001      0.1526
    9982   9980  109.5    0.1091   5.3665      0.1090
    9981   9980   38.4    0.1091   5.2833      0.1090
   10000   9983  114.8    0.1527 116.4570      0.1526
    9985   9983   99.0    0.1412  18.6182      0.1410
    9984   9983  136.4    0.1091  16.0484      0.1090
   10005  10000   82.1    0.1424 174.5740      0.1410
   10002  10000  103.4    0.1527 116.8710      0.1526
   10001  10000   98.2    0.1091 114.7582      0.1090
Wrote pdb files with previous and current coordinates
[wagner:26697] *** Process received signal ***
[wagner:26697] Signal: Segmentation fault (11)
[wagner:26697] Signal code: Address not mapped (1)
[wagner:26697] Failing at address: 0xf14c110
[wagner:26697] [ 0] /lib64/libpthread.so.0 [0x3ae4c0eb10]
[wagner:26697] [ 1] mdrun_mpi [0x711b49]
[wagner:26697] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 1 with PID 26697 on node  
wagner.lbpa.ens-cachan.fr exited on signal 11 (Segmentation fault).
--------------------------------------------------------------------------


I am aware that the problem probably lies with LINCS algorithm, but I  
am unsure about how to fix it.

Any help will be greatly appreciated.

Many thanks in advance!



Rohit Arora
Laboratoire de Biologie et de Pharmacologie Génétique Appliquée (CNRS UMR
8113)
Ecole Normale Supérieure, Cachan
France





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