Re: [ccp4bb] Double conformations of cysteine !

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CCP4bb <-- 2007 <-- July 2007 <-- 06 July 2007

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Subject: Re: Double conformations of cysteine !
From: "Miller, Mitchell D {- dot -} " mmiller {- at -} SLAC {- dot -} STANFORD {- dot -} EDU
Date: 2007-07-06

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Subject: Re: Double conformations of cysteine !
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2007-07-06

Subject: Re: Double conformations of cysteine !
From: "Sanishvili, Ruslan" rsanishvili {- at -} ANL {- dot -} GOV
Date: 2007-07-06

It seems odd from energetic considerations that there would be a
free-form amino acid when it "has a choice" to be involved in
energetically favorable interaction. It sounds doubly odd in the case of
a cystein involved in a disulfide bond.
Could it be that you are observing the effects of radiation decay? If
so, recollecting data with this in mind could help with refinement and
with avoiding artifacts in interpretation.
Sorry for not answering your question directly.
Cheers,
N.

Ruslan Sanishvili (Nukri), Ph.D.

GM/CA-CAT, Bld. 436, D007
Biosciences Division, ANL
9700 S. Cass Ave.
Argonne, IL 60439

Tel: (630)252-0665
Fax: (630)252-0667
rsanishvili@anl.gov

-----Original Message-----
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of
Prasenjit Bhaumik
Sent: Friday, July 06, 2007 12:46 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Double conformations of cysteine !

Hello,
We are trying to refine a structure using REFMAC and we are facing
problem in refining the double conformations of a cysteine residue. One
conformation is involved in formation of a disulfide linkage and other
conformation is free. Is there any way to define the restraints so that
both the conformations can be refined.

With kind regards,

Prasenjit

--
Prasenjit Bhaumik, Ph.D.
Protein Structure Section
Macromolecular Crystallography Laboratory National Cancer Institute at
Frederick 1050 Boyles Street, Building-539, Room-145 P.O. Box B,
Frederick, MD-21702, USA
Phone: 301-846-1974, Fax: 301-846-7101
E-mail: bhaumik@ncifcrf.gov

-------------------------------------------------

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CCP4bb <-- 2007 <-- July 2007 <-- 06 July 2007

Previous message:
Subject: Re: Double conformations of cysteine !
From: "Miller, Mitchell D {- dot -} " mmiller {- at -} SLAC {- dot -} STANFORD {- dot -} EDU
Date: 2007-07-06

Next message:
Subject: Re: Double conformations of cysteine !
From: Jacob Keller j-keller2 {- at -} MD {- dot -} NORTHWESTERN {- dot -} EDU
Date: 2007-07-06