Re: [AMBER] parameter file for modified nucleosides (O6-methyl guanine)

From: N.R. Jena <nrjena.gmail.com>
Date: Thu, 4 Mar 2010 16:10:13 +0530

Hi,
> but the ones I checked did not appear to be defined in your frcmod file.

Thank you so much. Which parameters you did not find from the
6OG.frcmod file that should actually be there?

On Tue, Mar 2, 2010 at 11:07 PM, Jason Swails <jason.swails.gmail.com> wrote:
> Hello,
>
> On Tue, Mar 2, 2010 at 11:59 AM, N.R. Jena <nrjena.gmail.com> wrote:
>> Thank you very much Prof. Case. There was no error message. It was like:
>>
>> {I am attaching herewith the .prepin and .frcmod files as well.}
>>
>> Building topology.
>> Building atom parameters.
>> Building bond parameters.
>> Could not find bond parameter for: OS - O2
>> Could not find bond parameter for: CK - P
>
> These are the error messages, same with the angle parameters and
> dihedral parameters below them.
>
>> Building angle parameters.
>> Could not find angle parameter: OS - O2 - P
>> Could not find angle parameter: CT - OS - O2
>> Could not find angle parameter: H5 - CK - P
>> Could not find angle parameter: CK - P - O2
>> Could not find angle parameter: CK - P - O2
>> Could not find angle parameter: CK - P - OS
>> Could not find angle parameter: NB - CK - P
>> Could not find angle parameter: N* - CK - P
>
> Missing angle parameters
>
>> Building proper torsion parameters.
>>  ** No torsion terms for  OS-O2-P-O2
>>  ** No torsion terms for  OS-O2-P-OS
>>  ** No torsion terms for  CT-OS-O2-P
>>  ** No torsion terms for  H5-CK-P-O2
>>  ** No torsion terms for  H5-CK-P-O2
>>  ** No torsion terms for  H5-CK-P-OS
>>  ** No torsion terms for  NB-CK-P-O2
>>  ** No torsion terms for  NB-CK-P-O2
>>  ** No torsion terms for  NB-CK-P-OS
>>  ** No torsion terms for  N*-CK-P-O2
>>  ** No torsion terms for  N*-CK-P-O2
>>  ** No torsion terms for  N*-CK-P-OS
>
> Missing dihedral parameters
>
>> Building improper torsion parameters.
>> old PREP-specified impropers:
>>  <6OG 7>:  C4   C8   N9   C1'
>>  <6OG 7>:  C5   N9   C4   N3
>>  <6OG 7>:  N2   N3   C2   N1
>>  <6OG 7>:  C2   H57  N2   H59
>>  <6OG 7>:  C5   N1   C6   O6
>>  <6OG 7>:  C6   C4   C5   N7
>>  <6OG 7>:  H55  N9   C8   N7
>>  total 630 improper torsions applied
>>  7 improper torsions in old prep form
>> Building H-Bond parameters.
>> Parameter file was not saved.
>
> The prmtop will not be saved without specifying those parameters
> listed above.  They are not recognized by leap.  Your frcmod file is
> large, so I didn't go through all of these parameters carefully, but
> the ones I checked did not appear to be defined in your frcmod file.
> If I had to guess where these missing parameters were coming from, I'd
> probably guess bonds across residues (since if you just created an
> frcmod from the prepin file for the O6G residue, it would not
> necessarily have parameters for the connections between O6G and
> neighbouring residues if your atom types differed from "typical"
> nucleic acid atom types.  Whether or not this is correct, though,
> you'll have to supply these parameters before a prmtop can be created.
>
> Good luck!
> Jason
>
> --
> ---------------------------------------
> Jason M. Swails
> Quantum Theory Project,
> University of Florida
> Ph.D. Graduate Student
> 352-392-4032
>
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> AMBER mailing list
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>

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Received on Thu Mar 04 2010 - 03:00:03 PST
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