[ccp4bb] Unusual Difference Fourier near Methionines

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

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Subject: Re: oxidised cys
From: Martyn Symmons martainn {- at -} OSHIOMAINS {- dot -} FREESERVE {- dot -} CO {- dot -} UK
Date: 2007-04-13

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Subject: Re: Unusual Difference Fourier near Methionines
From: David Schwefel rock34 {- at -} GMX {- dot -} NET
Date: 2007-04-13

Subject: Unusual Difference Fourier near Methionines
From: Ethayathulla Abdulsamath ethaya_aiims {- at -} REDIFFMAIL {- dot -} COM
Date: 2007-04-13

Dear all

I am doing one structure at 2.6A resolution where I found unusual density near methionines. Actually three methionines come close together nearby and I get difference even at 5sigma cutoff. I don't understand nature of the density. The amino acid sequnce is same I mean met by chemical sequncing so there is no change amino acid residues. I am sending the snapshot of the difference fourier observed at methionines. The crystal belong to R32 system with one molecule and biological trimer. In snapshot two of the methionines are symmetry related.

Details of the data collection.
Data collected at synchrotron

Overall Rsym = 6 % and I/sigma = 2.1. Completeness = 99%

Can anyone suggestion what could be chemical nature for the difference fourier.

Thanks in advance

Ethayathulla

###################################################
A.S.Ethayathulla,Ph.D.
Department of Biophysics
All India Institute of Medical Sciences
Ansari Nagar
New Delhi-110029
India.
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CCP4bb navigation

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

Previous message:
Subject: Re: oxidised cys
From: Martyn Symmons martainn {- at -} OSHIOMAINS {- dot -} FREESERVE {- dot -} CO {- dot -} UK
Date: 2007-04-13

Next message:
Subject: Re: Unusual Difference Fourier near Methionines
From: David Schwefel rock34 {- at -} GMX {- dot -} NET
Date: 2007-04-13