-------- Original Message --------
Subject: Re: [ccp4bb] Space group and R/Rfree value
Date: Wed, 01 Dec 2010 09:44:06 -0700
From: Maia Cherney <ch...@ualberta.ca>
To: Xiaopeng Hu <huxp...@mail.sysu.edu.cn>
References:
<643947201.129232.1291191478190.javamail.r...@zmbx0.sysu.edu.cn>
A dimer could be with a symmetry-related molecule in C2221, so there is
no need to have a dimer in the asym. unit.
Maia
Xiaopeng Hu wrote:
Dear all,
I am working on a data-set (2.3A) and the space group problem bothers me a
lot.The space group of the data-set could be C2221 or P212121, since our
protein functions as a dimer, and P212121 gives two molecular in the asym-uint,
I think P212121 is more reasonable than C2221.However with C2221, I can refine
the R/Rfree to 20/24 or lower, while with P212121 only to 26/30. Also Phenix
points out that the crystal is probably a twin with P212121 but is OK with
C2221.
I am not a real crystallographer, perhaps this problem is stupid, any help will
be appreciated!!
Best wishes,
Xiaopeng Hu
