[gmx-users] C-terminus residue name in Gromos43a1

Justin Lemkul jalemkul at vt.edu
Thu Feb 27 15:58:59 CET 2014



On 2/27/14, 9:48 AM, Francesca Vitalini wrote:
> I am using Gromacs 4.5.5. In my residuetypes.dat ACE is correctly listed as
> protein residue and pdb2gmx doesn't give any error about protein type.
>
> For clarity I copy here my pdb, the interesting parts of the aminoacids.rtp
> file and the pdb2gmx command.
>
> Thank you very much for any help you can give.
>
> #####################################
> FROM aminoacids.rtp
> #####################################
>
> [ ACE ]
>   [ atoms ]
>      CA   CH3   0.000     0
>       C     C   0.380     1
>       O     O  -0.380     1
>   [ bonds ]
>       C    CA   gb_26
>       C     O   gb_4
>       C    +N   gb_9
>   [ angles ]
>     CA     C     O    ga_30
>     CA     C    +N    ga_18
>      O     C    +N    ga_32
>   [ impropers ]
>      C    CA    +N     O    gi_1
>
> [ ALA ]
>   [ atoms ]
>      N     N    -0.28000     0
>      H     H     0.28000     0
>     CA   CH1     0.00000     1
>     CB   CH3     0.00000     1
>      C     C       0.380     2
>      O     O      -0.380     2
>   [ bonds ]
>      N     H    gb_2
>      N    CA    gb_20
>     CA     C    gb_26
>      C     O    gb_4
>      C    +N    gb_9
>     CA    CB    gb_26
>   [ angles ]
> ;  ai    aj    ak   gromos type
>     -C     N     H     ga_31
>      H     N    CA     ga_17
>     -C     N    CA     ga_30
>      N    CA     C     ga_12
>     CA     C    +N     ga_18
>     CA     C     O     ga_29
>      O     C    +N     ga_32
>      N    CA    CB     ga_12
>      C    CA    CB     ga_12
>   [ impropers ]
> ;  ai    aj    ak    al   gromos type
>      N    -C    CA     H     gi_1
>      C    CA    +N     O     gi_1
>     CA     N     C    CB     gi_2
>   [ dihedrals ]
> ;  ai    aj    ak    al   gromos type
>    -CA    -C     N    CA     gd_4
>     -C     N    CA     C     gd_19
>      N    CA     C    +N     gd_20
>
> [ NAC ]
>   [ atoms ]
>          N     N    -0.28000     0
>          H     H     0.28000     0
>         CA   CH3     0.00000     0
>   [ bonds ]
>          N    CA    gb_20
>          N     H    gb_2
>         -C     N    gb_9
>   [ angles ]
> ;  ai    aj    ak   gromos type
>         -C     N     H     ga_31
>          H     N    CA     ga_17
>         -C     N    CA     ga_30
>   [ impropers ]
> ;  ai    aj    ak    al   gromos type
>      N    -C    CA     H     gi_1
>   [ dihedrals ]
> ;  ai    aj    ak    al   gromos type
>    -CA    -C     N    CA     gd_4
>
>
> #####################################
> pdb file
> #####################################
>
> TITLE    ACETYL-ALANINE-METHYLAMIDE
> REMARK   GENERATED BY CUTTING OUT RESIDUE 14 TO 16 FROM FROM 2KSZ.PDB SEQ 1
> MODEL        1
> ATOM    1   1HH3  ACE A  1       9.955  -1.448  -7.763  1.00
> 0.00           H
> ATOM    2   CA   ACE A  1      10.830  -2.612  -7.822  1.00  0.00
> C
> ATOM    3   C     ACE A  1      10.355  -3.683  -6.846  1.00
> 0.00           C
> ATOM    4   O     ACE A  1      10.264  -4.861  -7.196  1.00
> 0.00           O
> ATOM    5   2HH3  ACE A  1      12.264  -2.204  -7.476  1.00
> 0.00           H
> ATOM    6   3HH3  ACE A  1      10.814  -3.010  -8.826  1.00
> 0.00           H
> ATOM    7   N     ALA A  2      10.042  -3.264  -5.625  1.00
> 0.00           N
> ATOM    8   CA    ALA A  2       9.563  -4.193  -4.609  1.00
> 0.00           C
> ATOM    9   C     ALA A  2       8.170  -4.706  -4.969  1.00
> 0.00           C
> ATOM    10  O     ALA A  2       7.806  -5.832  -4.630  1.00
> 0.00           O
> ATOM    11  CB    ALA A  2       9.507  -3.492  -3.251  1.00
> 0.00           C
> ATOM    12  H     ALA A  2      10.127  -2.310  -5.408  1.00
> 0.00           H
> ATOM    13  HA    ALA A  2      10.248  -5.025  -4.538  1.00
> 0.00           H
> ATOM    14  HB1   ALA A  2       9.115  -4.175  -2.509  1.00
> 0.00           H
> ATOM    15  HB2   ALA A  2       8.867  -2.625  -3.317  1.00
> 0.00           H
> ATOM    16  HB3   ALA A  2      10.502  -3.185  -2.963  1.00
> 0.00           H
> ATOM    17  N     NAC A  3       7.398  -3.868  -5.656  1.00
> 0.00           N
> ATOM    18  CA    NAC A  3       6.046  -4.242  -6.057  1.00
> 0.00           C
> ATOM    19  1HH3  NAC A  3       6.078  -5.329  -7.127  1.00
> 0.00           H
> ATOM    20  2HH3  NAC A  3       5.308  -3.015  -6.599  1.00
> 0.00           H
> ATOM    21  H     NAC A  3       7.743  -2.984  -5.899  1.00
> 0.00           H
> ATOM    22  3HH3  NAC A  3       5.512  -4.613  -5.197  1.00
> 0.00           H
> TER
>
>
>
> #####################################
> pdb2gmx
> #####################################
>
>
> pdb2gmx -f Ac_A_NHMe/Ac_A_NHMe_gromos.pdb -o Ac_A_NHMe/Ac_A_NHMe.gro -p
> Ac_A_NHMe/Ac_A_NHMe.top -i Ac_A_NHMe/Ac_A_NHMe.itp -n
> Ac_A_NHMe/Ac_A_NHMe.ndx -q Ac_A_NHMe/Ac_A_NHMe.pdb  -ignh -ter
>                           :-)  G  R  O  M  A  C  S  (-:
>
>                       Gyas ROwers Mature At Cryogenic Speed
>
>                              :-)  VERSION 4.5.5  (-:
>
>          Written by Emile Apol, Rossen Apostolov, Herman J.C. Berendsen,
>        Aldert van Buuren, Pär Bjelkmar, Rudi van Drunen, Anton Feenstra,
>          Gerrit Groenhof, Peter Kasson, Per Larsson, Pieter Meulenhoff,
>             Teemu Murtola, Szilard Pall, Sander Pronk, Roland Schulz,
>                  Michael Shirts, Alfons Sijbers, Peter Tieleman,
>
>                 Berk Hess, David van der Spoel, and Erik Lindahl.
>
>         Copyright (c) 1991-2000, University of Groningen, The Netherlands.
>              Copyright (c) 2001-2010, The GROMACS development team at
>          Uppsala University & The Royal Institute of Technology, Sweden.
>              check out http://www.gromacs.org for more information.
>
>           This program is free software; you can redistribute it and/or
>            modify it under the terms of the GNU General Public License
>           as published by the Free Software Foundation; either version 2
>               of the License, or (at your option) any later version.
>
>                                 :-)  pdb2gmx  (-:
>
> Option     Filename  Type         Description
> ------------------------------------------------------------
>    -f Ac_A_NHMe/Ac_A_NHMe_gromos.pdb  Input        Structure file: gro g96
> pdb
>                                     tpr etc.
>    -o Ac_A_NHMe/Ac_A_NHMe.gro  Output       Structure file: gro g96 pdb etc.
>    -p Ac_A_NHMe/Ac_A_NHMe.top  Output       Topology file
>    -i Ac_A_NHMe/Ac_A_NHMe.itp  Output       Include file for topology
>    -n Ac_A_NHMe/Ac_A_NHMe.ndx  Output, Opt! Index file
>    -q Ac_A_NHMe/Ac_A_NHMe.pdb  Output, Opt! Structure file: gro g96 pdb etc.
>
> Option       Type   Value   Description
> ------------------------------------------------------
> -[no]h       bool   no      Print help info and quit
> -[no]version bool   no      Print version info and quit
> -nice        int    0       Set the nicelevel
> -chainsep    enum   id_or_ter  Condition in PDB files when a new chain
> should
>                              be started (adding termini): id_or_ter,
>                              id_and_ter, ter, id or interactive
> -merge       enum   no      Merge multiple chains into a single
>                              [moleculetype]: no, all or interactive
> -ff          string select  Force field, interactive by default. Use -h for
>                              information.
> -water       enum   select  Water model to use: select, none, spc, spce,
>                              tip3p, tip4p or tip5p
> -[no]inter   bool   no      Set the next 8 options to interactive
> -[no]ss      bool   no      Interactive SS bridge selection
> -[no]ter     bool   yes     Interactive termini selection, instead of
> charged
>                              (default)
> -[no]lys     bool   no      Interactive lysine selection, instead of charged
> -[no]arg     bool   no      Interactive arginine selection, instead of
> charged
> -[no]asp     bool   no      Interactive aspartic acid selection, instead of
>                              charged
> -[no]glu     bool   no      Interactive glutamic acid selection, instead of
>                              charged
> -[no]gln     bool   no      Interactive glutamine selection, instead of
>                              neutral
> -[no]his     bool   no      Interactive histidine selection, instead of
>                              checking H-bonds
> -angle       real   135     Minimum hydrogen-donor-acceptor angle for a
>                              H-bond (degrees)
> -dist        real   0.3     Maximum donor-acceptor distance for a H-bond
> (nm)
> -[no]una     bool   no      Select aromatic rings with united CH atoms on
>                              phenylalanine, tryptophane and tyrosine
> -[no]ignh    bool   yes     Ignore hydrogen atoms that are in the coordinate
>                              file
> -[no]missing bool   no      Continue when atoms are missing, dangerous
> -[no]v       bool   no      Be slightly more verbose in messages
> -posrefc     real   1000    Force constant for position restraints
> -vsite       enum   none    Convert atoms to virtual sites: none, hydrogens
>                              or aromatics
> -[no]heavyh  bool   no      Make hydrogen atoms heavy
> -[no]deuterate bool no      Change the mass of hydrogens to 2 amu
> -[no]chargegrp bool yes     Use charge groups in the .rtp file
> -[no]cmap    bool   yes     Use cmap torsions (if enabled in the .rtp file)
> -[no]renum   bool   no      Renumber the residues consecutively in the
> output
> -[no]rtpres  bool   no      Use .rtp entry names as residue names
>
>
> Select the Force Field:
>  From current directory:
>   1: GROMOS96 43a1 force field
>  From '/usr/share/gromacs/top':
>   2: AMBER03 protein, nucleic AMBER94 (Duan et al., J. Comp. Chem. 24,
> 1999-2012, 2003)
>   3: AMBER94 force field (Cornell et al., JACS 117, 5179-5197, 1995)
>   4: AMBER96 protein, nucleic AMBER94 (Kollman et al., Acc. Chem. Res. 29,
> 461-469, 1996)
>   5: AMBER99 protein, nucleic AMBER94 (Wang et al., J. Comp. Chem. 21,
> 1049-1074, 2000)
>   6: AMBER99SB protein, nucleic AMBER94 (Hornak et al., Proteins 65,
> 712-725, 2006)
>   7: AMBER99SB-ILDN protein, nucleic AMBER94 (Lindorff-Larsen et al.,
> Proteins 78, 1950-58, 2010)
>   8: AMBERGS force field (Garcia & Sanbonmatsu, PNAS 99, 2782-2787, 2002)
>   9: CHARMM27 all-atom force field (with CMAP) - version 2.0
> 10: GROMOS96 43a1 force field
> 11: GROMOS96 43a2 force field (improved alkane dihedrals)
> 12: GROMOS96 45a3 force field (Schuler JCC 2001 22 1205)
> 13: GROMOS96 53a5 force field (JCC 2004 vol 25 pag 1656)
> 14: GROMOS96 53a6 force field (JCC 2004 vol 25 pag 1656)
> 15: OPLS-AA/L all-atom force field (2001 aminoacid dihedrals)
> 16: [DEPRECATED] Encad all-atom force field, using full solvent charges
> 17: [DEPRECATED] Encad all-atom force field, using scaled-down vacuum
> charges
> 18: [DEPRECATED] Gromacs force field (see manual)
> 19: [DEPRECATED] Gromacs force field with hydrogens for NMR
> 1
>
> Using the Gromos43a1_modifiedwithNAC force field in directory
> ./gromos43a1_modifiedwithNAC.ff
>
> Opening force field file ./gromos43a1_modifiedwithNAC.ff/watermodels.dat
>
> Select the Water Model:
>   1: SPC    simple point charge, recommended
>   2: SPC/E  extended simple point charge
>   3: None
> 1
> Opening force field file ./gromos43a1_modifiedwithNAC.ff/aminoacids.r2b
> Reading Ac_A_NHMe/Ac_A_NHMe_gromos.pdb...
> Read 'ACETYL-ALANINE-METHYLAMIDE', 10 atoms
>
> Back Off! I just backed up Ac_A_NHMe/Ac_A_NHMe.pdb to
> Ac_A_NHMe/#Ac_A_NHMe.pdb.5#
> Analyzing pdb file
> Splitting chemical chains based on TER records or chain id changing.
> There are 2 chains and 0 blocks of water and 0 residues with 10 atoms
>
>    chain  #res #atoms
>    1 'A'     1      1
>    2 ' '     3      9
>

This tells you the problem.  pdb2gmx thinks you have multiple chains.  The 
problem comes from some bad formatting in your input .pdb file.  I can't tell 
what exactly is wrong from the copied-and-pasted .pdb file since the email 
formatting hosed everything.  But something is broken from whatever 
manipulations you have made, which leads to...

<snip>

> Processing chain 1 'A' (1 atoms, 1 residues)

pdb2gmx thinking that ACE only has one atom!  From what I can see, it seems that 
the residue name and chain identifier for the CA atom is shifted one column to 
the left, which leads to misinterpretation of everything.  Perhaps that is an 
artifact of the email line wrapping, but that's what I see.  Everything else 
seems to be properly lined up.

-Justin

> Identified residue ACE1 as a starting terminus.
> Identified residue ACE1 as a ending terminus.
> 8 out of 8 lines of specbond.dat converted successfully
> Select start terminus type for ACE-1
>   0: NH3+
>   1: NH2
>   2: None
> 2
> Start terminus ACE-1: None
> Select end terminus type for ACE-1
>   0: COO-
>   1: COOH
>   2: None
> 2
> End terminus ACE-1: None
>
> -------------------------------------------------------
> Program pdb2gmx, VERSION 4.5.5
> Source code file: /tmp/build/gromacs-4.5.5/src/kernel/pdb2top.c, line: 1034
>
> Fatal error:
> There is a dangling bond at at least one of the terminal ends. Select a
> proper terminal entry.
> For more information and tips for troubleshooting, please check the GROMACS
> website at http://www.gromacs.org/Documentation/Errors
> -------------------------------------------------------
>
>
> Francesca
>
>
> 2014-02-27 11:59 GMT+01:00 Justin Lemkul <jalemkul at vt.edu>:
>
>>
>>
>> On 2/27/14, 2:03 AM, Francesca Vitalini wrote:
>>
>>> Residue 2 is just alanine,the most standard amino acid ever.
>>>
>>>
>> What Gromacs version is this?  Is ACE correctly listed in residuetypes.dat
>> as a protein residue?  pdb2gmx will also tell you this if it warns that
>> residue 1 and 2 are not of the same type.
>>
>> -Justin
>>
>>
>>   Any help?
>>>
>>> Francesca.
>>>    Il 26/feb/2014 11:58 "Justin Lemkul" <jalemkul at vt.edu> ha scritto:
>>>
>>>
>>>>
>>>> On 2/26/14, 4:08 AM, Francesca Vitalini wrote:
>>>>
>>>>   Dear Justin
>>>>>
>>>>>
>>>>> 2014-02-25 19:07 GMT+01:00 Justin Lemkul <jalemkul at vt.edu>:
>>>>>
>>>>>
>>>>>
>>>>>> On 2/25/14, 12:56 PM, Francesca Vitalini wrote:
>>>>>>
>>>>>>    Dear Justin,
>>>>>>
>>>>>>>
>>>>>>> Thanks for your answer.
>>>>>>> However I noticed that I had made a mistake and there is no definition
>>>>>>> of
>>>>>>> NAC in GROMOS53a6, it was the .rtp file of OPLS-AA I was looking at.
>>>>>>>
>>>>>>> So defining a new residue-type in the rtp file is not as trivial as I
>>>>>>> had
>>>>>>> hoped.
>>>>>>> I followed the instructions given on the GROMACS wab page
>>>>>>> http://www.gromacs.org/Documentation/How-tos/Adding_
>>>>>>> a_Residue_to_a_Force_Field
>>>>>>>
>>>>>>> and copied the gromos43a1.ff folder and the residuetypes.dat file in
>>>>>>> my
>>>>>>> local directory.
>>>>>>> I have added the following definition of NAC to the
>>>>>>> gromos43a1.ff/aminoacids.rtp file
>>>>>>>
>>>>>>> [ NAC ]
>>>>>>>      [ atoms ]
>>>>>>>             N     N    -0.28000     0
>>>>>>>             H     H     0.28000     0
>>>>>>>            CA   CH3     0.00000     0
>>>>>>>      [ bonds ]
>>>>>>>             N    CA    gb_20
>>>>>>>             N     H    gb_2
>>>>>>>
>>>>>>>
>>>>>>>   You're missing a bond here, from N to -C.
>>>>>>
>>>>>>
>>>>>
>>>>> I hadn't add that as all the other residue types also don't have it
>>>>> defined. It seems to me that the bond is defined as C to N+ not the
>>>>> other
>>>>> way round. In this case however I have no N+ and the hydrogens are not
>>>>> defined, so how can I properly define that bond?
>>>>>
>>>>> I also tried to define the bond N to -C as gb_9 (ie the bond type of C
>>>>> to
>>>>> N+) but it leads to the exact same error message.
>>>>>
>>>>>
>>>>>   Ah, true, this isn't necessary.
>>>>
>>>>
>>>>
>>>>>        [ angles ]
>>>>>>
>>>>>>   ;  ai    aj    ak   gromos type
>>>>>>>            -C     N     H     ga_31
>>>>>>>             H     N    CA     ga_17
>>>>>>>            -C     N    CA     ga_30
>>>>>>>      [ impropers ]
>>>>>>> ;  ai    aj    ak    al   gromos type
>>>>>>>         N    -C    CA     H     gi_1
>>>>>>>      [ dihedrals ]
>>>>>>> ;  ai    aj    ak    al   gromos type
>>>>>>>       -CA    -C     N    CA     gd_4
>>>>>>>
>>>>>>> and then tried again the pdb2gmx command as following and obtained
>>>>>>> this
>>>>>>> error
>>>>>>> Fatal error:
>>>>>>> There is a dangling bond at at least one of the terminal ends. Select
>>>>>>> a
>>>>>>> proper terminal entry.
>>>>>>> For more information and tips for troubleshooting, please check the
>>>>>>> GROMACS
>>>>>>> website at http://www.gromacs.org/Documentation/Errors
>>>>>>>
>>>>>>>
>>>>>>> Evidently I have not defined correctly my NAC residue. However, I am
>>>>>>> not
>>>>>>> sure of how to correctly define the bonds in this specific case. Could
>>>>>>> you
>>>>>>> possibly identify the error and/or point me where to find detailed
>>>>>>> information? I have already looked at the manual but haven't been able
>>>>>>> to
>>>>>>> come up with successful definition.
>>>>>>>
>>>>>>>
>>>>>>>    You need to use pdb2gmx -ter and select "None" for the C-terminus,
>>>>>>>
>>>>>> otherwise pdb2gmx tries to build a carboxylate.  When it can't find the
>>>>>> atoms it needs to do this, it fails.
>>>>>>
>>>>>>
>>>>>>   I do use the -ter "None" option for both termini and the error is
>>>>> still
>>>>> present. What I find interesting is this part of the pdb2gmx output
>>>>>
>>>>> Select start terminus type for ACE-1
>>>>>     0: NH3+
>>>>>     1: NH2
>>>>>     2: None
>>>>> 2
>>>>> Start terminus ACE-1: None
>>>>> Select end terminus type for ACE-1
>>>>>     0: COO-
>>>>>     1: COOH
>>>>>     2: None
>>>>> 2
>>>>> End terminus ACE-1: None
>>>>>
>>>>>
>>>>> where it looks like that ACE is the end terminus, not NAC, despite my
>>>>> pdb
>>>>> looks like the following. Any suggestions?
>>>>>
>>>>>
>>>>>   What is residue 2?  Is it anything non-standard?
>>>>
>>>> -Justin
>>>>
>>>> --
>>>> ==================================================
>>>>
>>>> Justin A. Lemkul, Ph.D.
>>>> Ruth L. Kirschstein NRSA Postdoctoral Fellow
>>>>
>>>> Department of Pharmaceutical Sciences
>>>> School of Pharmacy
>>>> Health Sciences Facility II, Room 601
>>>> University of Maryland, Baltimore
>>>> 20 Penn St.
>>>> Baltimore, MD 21201
>>>>
>>>> jalemkul at outerbanks.umaryland.edu | (410) 706-7441
>>>> http://mackerell.umaryland.edu/~jalemkul
>>>>
>>>> ==================================================
>>>> --
>>>> Gromacs Users mailing list
>>>>
>>>> * Please search the archive at http://www.gromacs.org/
>>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>>
>>>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
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>>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>>>> send a mail to gmx-users-request at gromacs.org.
>>>>
>>>>
>> --
>> ==================================================
>>
>> Justin A. Lemkul, Ph.D.
>> Ruth L. Kirschstein NRSA Postdoctoral Fellow
>>
>> Department of Pharmaceutical Sciences
>> School of Pharmacy
>> Health Sciences Facility II, Room 601
>> University of Maryland, Baltimore
>> 20 Penn St.
>> Baltimore, MD 21201
>>
>> jalemkul at outerbanks.umaryland.edu | (410) 706-7441
>> http://mackerell.umaryland.edu/~jalemkul
>>
>> ==================================================
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at http://www.gromacs.org/
>> Support/Mailing_Lists/GMX-Users_List before posting!
>>
>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>> * For (un)subscribe requests visit
>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>> send a mail to gmx-users-request at gromacs.org.
>>
>
>
>

-- 
==================================================

Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 601
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

==================================================


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