[ccp4bb] tortion angle restraints in REFMAC

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

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

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

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
--
Huiying Li, Ph. D
Department of Molecular Biology and Biochemistry
Natural Sciences I, Rm 2443
University of California at Irvine
Irvine, CA 92697, USA
Tel: 949-824-4322(or -1953); Fax: 949-824-3280
email: hli@uci.edu

CCP4bb navigation

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

Previous message:
Subject: Phaser job on CCP4 suite
From: wangsa tirta ismaya wangsatirta {- at -} GMAIL {- dot -} COM
Date: 2008-12-03

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