Crystallography‎ > ‎Phasing‎ > ‎

Seleno methionines

Mutagenesis to introduce Met in protein missing it:

Leahy et al. Crystallization of a fragment of human fibronectin: introduction of methionine by site-directed mutagenesis to allow phasing via selenomethionine. Proteins (1994) vol. 19 (1) pp. 48-54

Introduction of Leu->Met seems to be the best choice.

Consider a multiple sequence alignment:
- ignore the ones that may have functional importance,
- ignore the ones that may be present in loops or may be surface exposed (best to have the Se-Met in well-ordered regions),
- try multiple combinations of Leu->Met substitutions.

Ohter successful cases:
Gassner, N. C., Baase, W. A. & Matthews, B. W. (1996). Proc. Natl Acad. Sci. USA, 93, 12155-12158
Jones, D. T., Taylor, W. R. & Thornton, J. M. (1992). Comput. Appl. Biosci. 8, 275-282