Sorry - I should have added that, yes, there are 2 identical peptide chains that should be parallel coiled-coil.
Any advice gratefully received.
Ed
-----Original Message-----
From: cockburn [mailto:[log in to unmask]]
Sent: Fri 3/28/2008 1:35 PM
To: Thomas Edwards
Subject: Re: [ccp4bb] MolRep of coiled coils
Hi Thomas,
Does your coiled-coil consist of two polypeptide chains, and are their
sequences identical? Do you expect it to be a parallel or anti-parallel
coiled-coil?
Yours
Joe
Thomas Edwards a écrit :
> 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
>
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