I am working on a protein having 360 residues. In its sequence there are 3
Met and 5 free Cys.
I will need MAD to solve the structure since based on the sequence the
closest homologue has 20% identity
I suppose MR would be very unlikely to
work
so I would like to express a selenium derivative to exploit MAD.
Looking in the literature 1 Se-Met every 120 residues seems not to comply
the threshold to get a good anomalous signal. For this reason I would like
to exploit both Met and Cys so I would have 8 seleniums per 360 residues.
Could somenone suggest a reference to a protocol to express the double
mutant protein in NON auxotrophic strains of E. coli which you have
experienced working efficiently?
Thanks
