I am using Gromacs 4.0.5 and in my ffamber03.rtp I can see that the charges are as you mentioned.
"H1 amber99_17 0.35200 19" But in my top file the H1 atom of the type amber99_17 gets replaced by the amber99_25 type so what should have been amber99_17 1 DG5 H1 19 0.35200 1.008 ; is written by pdb2gmx as amber99_25 1 DG5 H1 19 0.4422 1.008 ; How can I make amber generate the topology with the right atomtype and charge in this case?. Thanks in advance. my top file: 1 amber99_43 1 DG5 O5' 1 -0.6318 16 ; qtot -0.6318 2 amber99_25 1 DG5 H5T 2 0.4422 1.008 ; qtot -0.1896 3 amber99_11 1 DG5 C5' 3 -0.0069 12.01 ; qtot -0.1965 4 amber99_19 1 DG5 H5'1 4 0.0754 1.008 ; qtot -0.1211 5 amber99_19 1 DG5 H5'2 5 0.0754 1.008 ; qtot -0.0457 6 amber99_11 1 DG5 C4' 6 0.1629 12.01 ; qtot 0.1172 7 amber99_19 1 DG5 H4' 7 0.1176 1.008 ; qtot 0.2348 8 amber99_44 1 DG5 O4' 8 -0.3691 16 ; qtot -0.1343 9 amber99_11 1 DG5 C1' 9 0.0358 12.01 ; qtot -0.0985 10 amber99_20 1 DG5 H1' 10 0.1746 1.008 ; qtot 0.0761 11 amber99_40 1 DG5 N9 11 0.0577 14.01 ; qtot 0.1338 12 amber99_6 1 DG5 C8 12 0.0736 12.01 ; qtot 0.2074 13 amber99_24 1 DG5 H8 13 0.1997 1.008 ; qtot 0.4071 14 amber99_36 1 DG5 N7 14 -0.5725 14.01 ; qtot -0.1654 15 amber99_4 1 DG5 C5 15 0.1991 12.01 ; qtot 0.0337 16 amber99_2 1 DG5 C6 16 0.4918 12.01 ; qtot 0.5255 17 amber99_41 1 DG5 O6 17 -0.5699 16 ; qtot -0.0444 18 amber99_35 1 DG5 N1 18 -0.5053 14.01 ; qtot -0.5497 19 amber99_25 1 DG5 H1 19 0.4422 1.008 ; qtot -0.1075 20 amber99_3 1 DG5 C2 20 0.7432 12.01 ; qtot 0.6357 21 amber99_38 1 DG5 N2 21 -0.923 14.01 ; qtot -0.2873 22 amber99_17 1 DG5 H21 22 0.4235 1.008 ; qtot 0.1362 23 amber99_17 1 DG5 H22 23 0.4235 1.008 ; qtot 0.5597 24 amber99_37 1 DG5 N3 24 -0.6636 14.01 ; qtot -0.1039 25 amber99_4 1 DG5 C4 25 0.1814 12.01 ; qtot 0.0775 26 amber99_11 1 DG5 C3' 26 0.0713 12.01 ; qtot 0.1488 27 amber99_19 1 DG5 H3' 27 0.0985 1.008 ; qtot 0.2473 28 amber99_11 1 DG5 C2' 28 -0.0854 12.01 ; qtot 0.1619 29 amber99_18 1 DG5 H2'1 29 0.0718 1.008 ; qtot 0.2337 30 amber99_18 1 DG5 H2'2 30 0.0718 1.008 ; qtot 0.3055 31 amber99_44 1 DG5 O3' 31 -0.5232 16 ; qtot -0.2177 ..... ....... ..... ________________________________________ From: gmx-users-boun...@gromacs.org [gmx-users-boun...@gromacs.org] On Behalf Of Justin A. Lemkul [jalem...@vt.edu] Sent: Monday, August 29, 2011 2:41 AM To: Discussion list for GROMACS users Subject: Re: [gmx-users] amber DNA non-integer charge Kamesh Narasimhan wrote: > Hil, > > I am trying to simulate a protein-DNA structure using amber03 and end up > having a non-integer charge in topology generation . From the webpage of > ffamber on NA-simulations, I could see this below instruction > > "However, for nucleic acids this also often causes pdb2gmx to replace an H > atom in the first residue of all nucleic acid chains with an incorrect H > atom, resulting in non-neutral charge. The correct atom is generally replaced > with an atom of type amberXX_25 (hydroxyl H), as pdb2gmx treats it as a > terminal hydrogen". > > I replaced the aminoacids.dat contents with aminoacids-NA.dat contents and > therefore not sure how the non-integer originates. > > In my top file I can see this residue of the type "amber99_25" . How do I > correct for the atom-type and charge in this case ? > > " amber99_25 1 DG5 H5T 2 0.4422 1.008 ; qtot > -0.1896" > > > My top file section: > > nr type resnr residue atom cgnr charge mass typeB > chargeB massB > 1 amber99_43 1 DG5 O5' 1 -0.6318 16 ; qtot > -0.6318 > 2 amber99_25 1 DG5 H5T 2 0.4422 1.008 ; qtot > -0.1896 > 3 amber99_11 1 DG5 C5' 3 -0.0069 12.01 ; qtot > -0.1965 > 4 amber99_19 1 DG5 H5'1 4 0.0754 1.008 ; qtot > -0.1211 > 5 amber99_19 1 DG5 H5'2 5 0.0754 1.008 ; qtot > -0.0457 > 6 amber99_11 1 DG5 C4' 6 0.1629 12.01 ; qtot > 0.1172 > 7 amber99_19 1 DG5 H4' 7 0.1176 1.008 ; qtot > 0.2348 > 8 amber99_44 1 DG5 O4' 8 -0.3691 16 ; qtot > -0.1343 > 9 amber99_11 1 DG5 C1' 9 0.0358 12.01 ; qtot > -0.0985 > 10 amber99_20 1 DG5 H1' 10 0.1746 1.008 ; qtot > 0.0761 > 11 amber99_40 1 DG5 N9 11 0.0577 14.01 ; qtot > 0.1338 > 12 amber99_6 1 DG5 C8 12 0.0736 12.01 ; qtot > 0.2074 > 13 amber99_24 1 DG5 H8 13 0.1997 1.008 ; qtot > 0.4071 > 14 amber99_36 1 DG5 N7 14 -0.5725 14.01 ; qtot > -0.1654 > 15 amber99_4 1 DG5 C5 15 0.1991 12.01 ; qtot > 0.0337 > 16 amber99_2 1 DG5 C6 16 0.4918 12.01 ; qtot > 0.5255 > 17 amber99_41 1 DG5 O6 17 -0.5699 16 ; qtot > -0.0444 > 18 amber99_35 1 DG5 N1 18 -0.5053 14.01 ; qtot > -0.5497 > 19 amber99_25 1 DG5 H1 19 0.4422 1.008 ; qtot > -0.1075 The charge on H1 is wrong. According to the DG5 .rtp entry (in the version 4.5.x series), the charge should be 0.352. -Justin > 20 amber99_3 1 DG5 C2 20 0.7432 12.01 ; qtot > 0.6357 > 21 amber99_38 1 DG5 N2 21 -0.923 14.01 ; qtot > -0.2873 > 22 amber99_17 1 DG5 H21 22 0.4235 1.008 ; qtot > 0.1362 > 23 amber99_17 1 DG5 H22 23 0.4235 1.008 ; qtot > 0.5597 > 24 amber99_37 1 DG5 N3 24 -0.6636 14.01 ; qtot > -0.1039 > 25 amber99_4 1 DG5 C4 25 0.1814 12.01 ; qtot > 0.0775 > 26 amber99_11 1 DG5 C3' 26 0.0713 12.01 ; qtot > 0.1488 > 27 amber99_19 1 DG5 H3' 27 0.0985 1.008 ; qtot > 0.2473 > 28 amber99_11 1 DG5 C2' 28 -0.0854 12.01 ; qtot > 0.1619 > 29 amber99_18 1 DG5 H2'1 29 0.0718 1.008 ; qtot > 0.2337 > 30 amber99_18 1 DG5 H2'2 30 0.0718 1.008 ; qtot > 0.3055 > 31 amber99_44 1 DG5 O3' 31 -0.5232 16 ; qtot > -0.2177 > .... > ..... > > My pdb file section: > ATOM 1 C5' DG5 A 1 28.937 -10.596 -28.986 1.00 95.46 C > ATOM 2 O5' DG5 A 1 30.060 -10.216 -29.774 1.00 95.82 O > ATOM 3 C4' DG5 A 1 29.239 -11.863 -28.212 1.00101.28 C > ATOM 4 O4' DG5 A 1 30.545 -11.736 -27.597 1.00102.88 O > ATOM 5 C3' DG5 A 1 28.300 -12.150 -27.052 1.00100.37 C > ATOM 6 O3' DG5 A 1 28.363 -13.527 -26.704 1.00104.13 O > ATOM 7 C2' DG5 A 1 28.913 -11.282 -25.960 1.00 95.28 C > ATOM 8 C1' DG5 A 1 30.395 -11.553 -26.200 1.00100.67 C > ATOM 9 N1 DG5 A 1 34.400 -10.292 -23.339 1.00 88.74 N > ATOM 10 C2 DG5 A 1 33.795 -11.515 -23.502 1.00 92.09 C > ATOM 11 N2 DG5 A 1 34.320 -12.542 -22.818 1.00 92.20 N > ATOM 12 N3 DG5 A 1 32.745 -11.722 -24.284 1.00100.66 N > ATOM 13 C4 DG5 A 1 32.342 -10.585 -24.901 1.00101.19 C > ATOM 14 C5 DG5 A 1 32.877 -9.321 -24.804 1.00 97.04 C > ATOM 15 C6 DG5 A 1 33.999 -9.114 -23.965 1.00 93.19 C > ATOM 16 O6 DG5 A 1 34.613 -8.059 -23.751 1.00 94.32 O > ATOM 17 N7 DG5 A 1 32.171 -8.426 -25.598 1.00 94.27 N > ATOM 18 C8 DG5 A 1 31.241 -9.155 -26.150 1.00 97.12 C > ATOM 19 N9 DG5 A 1 31.282 -10.474 -25.771 1.00100.33 N > > .... > ..... > > > thanks > kamesh-- > gmx-users mailing list gmx-users@gromacs.org > http://lists.gromacs.org/mailman/listinfo/gmx-users > Please search the archive at > http://www.gromacs.org/Support/Mailing_Lists/Search before posting! > Please don't post (un)subscribe requests to the list. Use the > www interface or send it to gmx-users-requ...@gromacs.org. > Can't post? Read http://www.gromacs.org/Support/Mailing_Lists > -- ======================================== Justin A. Lemkul Ph.D. Candidate ICTAS Doctoral Scholar MILES-IGERT Trainee Department of Biochemistry Virginia Tech Blacksburg, VA jalemkul[at]vt.edu | (540) 231-9080 http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin ======================================== -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists-- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists