FYI, I do know of one example of a solved structure where some of the
molecules in the ASU are poorly defined. In 1EKJ, 4 of the 8 molecules
in the ASU have low B-factors (mid 30s) and 4 have high B-factors
(50s-60s). In the unit cell these layers alternate. It is possible, if
everything else has been excluded, that your crystal has a similar
crystal-packing issue.
Cheers,
_______________________________________
Roger S. Rowlett
Gordon & Dorothy Kline Professor
Department of Chemistry
Colgate University
13 Oak Drive
Hamilton, NY 13346
tel: (315)-228-7245
ofc: (315)-228-7395
fax: (315)-228-7935
email: rrowl...@colgate.edu
On 4/29/2013 9:30 AM, sonali dhindwal wrote:
Dear Eleanor,
Thanks for the suggestion, I just checked on the Zanuda program, it is
also giving P1 as the best possible spacegroup for the molecule.
and by not refining well, I meant for the electron density which is
broken at many places at main chain, and poor electron density for the
side chains which are otherwise good in other chains.
Regards
--
Sonali Dhindwal
“Live as if you were to die tomorrow. Learn as if you were to live
forever.”
------------------------------------------------------------------------
*From:* Eleanor Dodson <eleanor.dod...@york.ac.uk>
*To:* CCP4BB@JISCMAIL.AC.UK
*Sent:* Monday, 29 April 2013 4:36 PM
*Subject:* Re: [ccp4bb] Poor electron density in some of the chains in
an asymmetric unit
There isnt much information here!
Funny that 3 chains are poor - does that mean one and a half
heterodimers?
I presume you have checked spacegroup? Zanuda will test to see if any
higher symmetry is present..
Eleanor
On 29 April 2013 06:02, sonali dhindwal <sonali11dhind...@yahoo.co.in
<mailto:sonali11dhind...@yahoo.co.in>> wrote:
Dear All,
We are working on a crystal structure with 12 molecules in an
asymmetric unit. It is a heteromer and each chain is made up of
two type of chains. Therefore there are 24 chains in an asymmetric
unit.
It is giving solution in P1. Rfactor and Rfree has reached 20.25
and 25.6 at a resolution of 1.8Angstrom
All the chains are refining well and have good electron density
except 3 chains which have very poor electron density in most of
the region.
Whereas, the crystal structure of variants of the same protein we
have solved earlier refined well and has very good electron
density in all the chains.
What could be the possible reason for these three chains which are
not refining properly. Any suggestions will be very useful.
Thanks and Regards
--
Sonali Dhindwal
“Live as if you were to die tomorrow. Learn as if you were to live
forever.”
