1d3f
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N-TERMINAL DOMAIN CORE METHIONINE MUTATION
OverviewOverview
Using heavily methionine-substituted T4 lysozyme as an example, it is, shown how the addition or deletion of a small number of methionines can, simplify the location of selenium sites for use in MAD phasing. By, comparing the X-ray data for a large number of singly substituted, lysozymes, it is shown that the optimal amino acid to be substituted by, methionine is leucine, followed, in order of preference, by phenylalanine, isoleucine and valine. The identification of leucine as the first choice, agrees with the ranking suggested by the Dayhoff mutation probability, i.e. by the frequency of amino-acid substitutions in the sequences of, related proteins. The ranking of the second and subsequent choices, however, differ significantly.
About this StructureAbout this Structure
1D3F is a Single protein structure of sequence from Bacteriophage t4 with CL and HED as ligands. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
ReferenceReference
Use of differentially substituted selenomethionine proteins in X-ray structure determination., Gassner NC, Matthews BW, Acta Crystallogr D Biol Crystallogr. 1999 Dec;55(Pt 12):1967-70. PMID:10666571
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