[ccp4bb] MolRep of coiled coils

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CCP4bb <-- 2008 <-- March 2008 <-- 28 March 2008

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Subject: too good R/Rfree with resolve
From: stefano ricagno ciciulus {- at -} HOTMAIL {- dot -} COM
Date: 2008-03-28

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Subject: Re: too good R/Rfree with resolve
From: Garib Murshudov garib {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2008-03-28

Subject: MolRep of coiled coils
From: Thomas Edwards T {- dot -} A {- dot -} Edwards {- at -} LEEDS {- dot -} AC {- dot -} UK
Date: 2008-03-28

Dear BB,

I am attempting molecular replacement with a 2.8A data set from crystals of a coiled coil of about 150 residues.
Probably p21212 but maybe p2221.

So far, Phaser, MolRep, Amore, Mr Bump, have not provided a good solution as judged by Z-scores, CCs, Rfactors, and whether there is any density outside the model (there should be - I'm using a slightly shorter model to search with).

One possible problem is that the coiled coil may not be straight. It may have a slight curve to it.
I have used models from the PDB that are straight or slightly curved, so far with no success.
I have tried a few different resolution cutoffs too.
I have tried single helix chains or dimeric coiled coils.

Is there anything special about MR with coiled coils?
Can anybody provide any tips/hints on MR with coiled coils??

Thanks
Ed

CCP4bb navigation

CCP4bb <-- 2008 <-- March 2008 <-- 28 March 2008

Previous message:
Subject: too good R/Rfree with resolve
From: stefano ricagno ciciulus {- at -} HOTMAIL {- dot -} COM
Date: 2008-03-28

Next message:
Subject: Re: too good R/Rfree with resolve
From: Garib Murshudov garib {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2008-03-28