[gmx-users] DNA simulations with GROMACS???

[Mark Abraham]

> Dear GROMACS users!
>
> Is it possible to model DNA with the help of GROMACS with AMBER ports?
> I've checked mailing-list and found that the only GROMCAS force field
> appropriate for modeling DNA is OPLS, but it does not provide good
> enough results for long DNA MD runs.
> The mailing-list suggested AMBER ports. I've managed to produce
> topology and coordinates files, solvate the system. But when I came to
> grompp step, I got the following error message:
>
> Program grompp, VERSION 3.3.1
> Source code file: grompp.c, line: 448
>
> Fatal error:
> number of coordinates in coordinate file (genbox.gro, 32804)
>              does not match topology (dick.top, 0)
> ---
> I've checked my dick.top file and it looks OK.

Unfortunately, it probably isn't... see
http://wiki.gromacs.org/index.php/Errors#Number_of_coordinates_in_coordinate_file_does_not_match_topology

> I've also checked
> ffamber99.rtp, ffamber99.atp, ffamber.hdb,ffamberbon.itp and several
> other files. I am not a programmer myself, but I checked the same sort
> of files for GROMOS force fields, they have different format

Yeah, that's fine.

> and I
> suspect that this is the reason for the error message. The program
> simply can't parse some files.
> Has someone tried modelling DNA in GROMACS with AMBER ports? Was it
> successful?

Don't know.

Mark