Re: [ccp4bb] High Rfac/Rfree for a 1.6A reso structure

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

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Subject: Re: High Rfac/Rfree for a 1.6A reso structure
From: Peter Zwart PHZwart {- at -} LBL {- dot -} GOV
Date: 2007-08-17

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From: Arun Malhotra malhotra {- at -} MIAMI {- dot -} EDU
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Subject: Re: High Rfac/Rfree for a 1.6A reso structure
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-08-17

There are obvious ones like - incomplete structure etc, but have you
tried TLS? Sometimes this can dramaticaly improve the R factors.

You seem to have lost of lot of the low resolution data - could this
mean you had overloads which naybe could be rescued.. That can down
grade the maps a good deal
Eleanor

Sabini, Elisabetta wrote:
> Dear all,
>
> I have a structure at 1.6A. At the end of refinement the Rfactor and Rfree
> are quite high (23/29.6%). Here are some info:
>
> Morphology of crystals: large but thin plates (150 x 400 x 20 microns)
> Number of residues: 160 (2 x 80); 103 water molecules
> Space group: C2
> Unit Cell: 47.75 33.61 91.04 90.000 103.635 90.000
>
> Data is a merge of a low resolution and high resolution sweep. The
> correlation between the two data sets is:
>
> DATA SETS NUMBER OF COMMON CORRELATION RATIO OF COMMON B-FACTOR
> #i #j REFLECTIONS BETWEEN i,j INTENSITIES (i/j) BETWEEN i,j
>
> 1 2 4049 0.973 1.0002 0.0001
>
> I include the data collection and refinement statistics in the attachment.
>
> Can you please suggest to me possible reasons for the high Rfact and Rfree?
>
> Thanks,
>
> Elisabetta.
>
>

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

Previous message:
Subject: Re: High Rfac/Rfree for a 1.6A reso structure
From: Peter Zwart PHZwart {- at -} LBL {- dot -} GOV
Date: 2007-08-17

Next message:
Subject: Re: nature cb3 response
From: Arun Malhotra malhotra {- at -} MIAMI {- dot -} EDU
Date: 2007-08-17