Dear Vito,
for SeMet have a look here:
http://strucbio.biologie.uni-konstanz.de/ccp4wiki/index.php/Expression_of_SeMet_labeled_proteins
Worked like a charm for E.coli and also for other expression hosts
with minor modifications
(https://www.nature.com/nature/journal/v516/n7529/full/nature14003.html#methods).
HTH
Guenter
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