Hi Peter,
How do you know you have crystallized the complex? Perhaps MR is not working because your crystals only contain the small protein.
good luck,
Eric
>
> Hi all,
>
> I have a small complex, one component is 13 kDa with structure available and
> the other is 7 kDa, which could not be able to grew crystals after lots of
> efforts. It grew crystals after methylation and diffracted to 2.3 A,
> however, I could not be able to solve the structure using the structure of
> the big component as a template for molecular replacement, and heavy atoms
> soaking was not successful. I plan to do selenomethionine expression
> next. Does the methylation change protein structures a lot? otherwise, why
> does molecular replacement not work? I would much appreciate any idea and
> suggestions how to solve the structure using the data and the template
> avaliable.
>
> Many thanks for your help.
>
> Peter
>
> ____________________________________________________________________________
> Date: Tue, 24 Nov 2009 18:27:49 +0100
> From: [log in to unmask]
> Subject: [ccp4bb] Methylation of macromolecular complexes
> To: [log in to unmask]
>
> Hi all,
> I have a question regarding the methylation of macromolecular complexes. Is
> there any report where a macromolecular complex has been successfully
> methylated and later on crystallized. Is methylation a method of choice to
> chemically modify macromolecular complexes where the entropical
> contributions by lysines might be a cause for not obtaining crystals, or is
> there any other better ways?
>
> thanks,
> Jan Rash
>
> ____________________________________________________________________________
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