Dear Appu,

It seems that the anisotropy server you used put the anisotropic corrections in 
the pdb, which got subsequently rejected by the refinement programs because of 
insufficient resolution.

The alternative is to apply anisotropic scaling to your reflection data, which 
is e.g. done by the UCLA anisotropy server. Using the scaled mtz should solve 
your problem.

Best,
Herman



Von: CCP4 bulletin board [mailto:[email protected]] Im Auftrag von Appu 
kumar
Gesendet: Donnerstag, 2. Juli 2015 05:17
An: [email protected]
Betreff: Re: [ccp4bb] ANISOU in pdb and density improvement

Hello All,
Sorry for giving incomplete information. The protein is 75KDa membrane protein 
and it exists as tetramer in ASU. Structure is solved by MR. Overall 
completeness of data is 98% wiith multiplicity of 4.8. Density looks great 
after refinement having ANISOU record in PDB.

Any suggestions and guidance will be much appreciated
Thanks you
Appu

On 1 July 2015 at 21:14, xaravich ivan 
<[email protected]<mailto:[email protected]>> wrote:
4 Angstrom resolution is pretty low and there has to be other info associated 
with that to get more help from here.
How big is your protein? How are you solving the phases? How complete is your 
data at that resolution? What kind of multiplicity are you getting? I think you 
have other issues that are much more pressing than what you are asking here!!!
As you are able to get 4A data it is evident that you can crystallize your 
protein. Congrats!!!! Now, concentrate on that and try to get higher resolution 
data from better diffracting crystals and it might be a much easier experience, 
(unless you trying to solve a huge ribosomal complex kind of protein and in 
that case 4 angs is amazing!!!!)
cheers

Ivan

On Wed, Jul 1, 2015 at 5:57 PM, Appu kumar 
<[email protected]<mailto:[email protected]>> wrote:
Dear CCP4 users,
I am refining a structure at 4A resolution. Crystal diffracted anisotropically 
and after refinement in both PHENIX and REFMAC, electron density in one of the 
domain of protein is represented by discontinuity and poor maps. Therefore i 
did the aniosotropy correction using anisotropy server. After anisotropy 
correction using anisotropy server, the electron density becomes resonable for 
4A map as evident by appearance of electron density around some bulky 
sidechains and discontinuity in electron density is diminished. When i look 
into the pdb, I found that pdb contain ANISOU records for each atoms.

I tried same things with other data sets and same data set again (data set 
described above) of same protein. After refinement, the ANISOU records are not 
present for each atoms in refined pdb and the electron density is discontinuous 
and poor.

I am wondering why one of the anisotropically corrected MTZ by diffraction 
server gives the ANISOU  records with the good density after refinement and 
other mtz file do not produce ANISOU record in pdb and poor density map.

I would appreciate your help regarding this issue.
Thank you
Appu


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