Re: [ccp4bb] tortion angle restraints in REFMAC

- Protein crystallography

Main steps:

- Protein purification
- Crystallisation

Special:

- Programs for crystallography
- X-ray detectors

Basic tutorials:

   - Chemistry
   - Protein
   - Peptide
   - Amino Acids

Xtal community:

- CCP4BB

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: tortion angle restraints in REFMAC
From: Huiying Li hli {- at -} CRYSTAL {- dot -} BIO {- dot -} UCI {- dot -} EDU
Date: 2008-12-03

Next message:
Subject: 1-butyl-2-methyl imidazolium chloride
From: Ronnie ronniewei {- at -} YAHOO {- dot -} COM
Date: 2008-12-03

Subject: Re: tortion angle restraints in REFMAC
From: Abhinav Kumar abhinavk {- at -} SLAC {- dot -} STANFORD {- dot -} EDU
Date: 2008-12-03

If you want to restrain the OH group to a plane, you need to include it
in the plane definition, and not the torsion definition.

Thanks
Abhinav

Stanford Synchrotron Radiation Laboratory
Joint Center for Structural Genomics
Mail Stop 99
Phone: (650) 926-2992
Fax: (650) 926-3292

Huiying Li wrote:
> I want to impose restraints during REFMAC refinement on the tortion
> angles that control the tilting of an OH group from a plane in a
> ligand bound to the protein. A few things that confused me:
>
> 1. In library cif file, should I just increase or decrease the
> tor.value_angle_esd if I want to loosen or tighten the restraits?
>
> 2. What is the meaning of the last column in torsion angle parameters:
> _chem_comp_tor.period, in cif file? In the PDB output file REFMAC also
> lists the RMS and WEIGHT for the torsion angles, period 1 through 4.
>
> 3. In REFMAC gui under Geometric parameters, there is only one user
> controlled weight for torsion. By changing the weight here, does it
> change the torsion weight for all 4 periods?
>
> Thanks in advance for the help.
>
> Huiying

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: tortion angle restraints in REFMAC
From: Huiying Li hli {- at -} CRYSTAL {- dot -} BIO {- dot -} UCI {- dot -} EDU
Date: 2008-12-03

Next message:
Subject: 1-butyl-2-methyl imidazolium chloride
From: Ronnie ronniewei {- at -} YAHOO {- dot -} COM
Date: 2008-12-03