[ccp4bb]: Can I find a zinc in a haystack?

[Jeff Taylor <JSTaylor@duke.edu>]

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Hi -

I have crystals of a 90KD protein that has a single zinc site.  Although
I have what should be a good model for molecular replacement, I haven't
been able to solve it.  I'm planning to try and substitute a Hg for the
Zinc in hopes of using the anomalous signal to determine the location of
the metal site (and there by solving the translation portion of the
molecular replacement).  Does this sound reasonable?

The Hg substitution may be difficult in this case, so I'm also wondering
if there is any possibility that I might be able to do the same thing
using the absorption edge of the zinc?  

I don't have much experience in these matters.  Would this simply be too
small a signal for this large of a protein?

All opinions are appreciated.  Thank you,

Jeff Taylor


-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Dr. Jeffrey S. Taylor       Duke University Medical Center
Department of Biochemistry  Box 3711, Nanaline Duke Bld  
Phone (919) 681-5266        Durham, NC 27710