[gmx-users] problem pdb2gmx and acetylation

[menica dibenedetto]

Dear all,
I have a problem with pdb2gmx function.
I want to create the gro file of an acetylated at N-term protein.
I copy here the head of the file:
ATOM   2016  HC  ACE     0      24.770 -62.381 -11.080                       H
ATOM   2015  CT  ACE     0      25.644 -61.867 -10.739                       C
ATOM   2017  HC  ACE     0      26.283 -61.657 -11.571                       H
ATOM   2018  HC  ACE     0      26.167 -62.480 -10.034                       H
ATOM   2013   C  ACE     0      25.231 -60.546 -10.063                       C
ATOM   2014   O  ACE     0      24.058 -60.199  -9.966                       O
TER
ATOM   2019   N  MET     1      26.336 -59.728  -9.542                       N
ATOM   2020   H  MET     1      27.236 -59.762  -9.976                       H
ATOM      1  CA  MET     1      26.144 -59.704  -8.063                       C

The problem is that the output error told me that the atoms labels of
ACE not correspond to the labels in the rtp file,
but I checked it and them corresponds:
Program pdb2gmx_d, VERSION 4.5.5
Source code file: pdb2gmx.c, line: 655
Fatal error:
Atom HC in residue ACE 0 was not found in rtp entry ACE with 6 atoms
while sorting atoms.

I used the amber99sb-ildn.ff

What can I do?
I added the acetylation using gaussian

thanks for the attention
Regards
domenica