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Published on: January 5, 2016
Stereochemical Course of Methyl Transfer by Cobalamin-Dependent Radical SAM Methyltransferase in Fosfomycin
Anna Schweifer1, Friedrich Hammerschmidt1
1Institute of Organic Chemistry , University of Vienna , Währingerstraße 38 , A-1090 Vienna , Austria.
Abstract:
The methyl groups of [ methyl-( S)]- and [ methyl-( R)]-[ methyl-D,T]-l-methionine fed to Streptomyces fradiae were incorporated into fosfomycin, which was chemically degraded to chiral AcONa. The enzymatic test gave the ( S)-configuration for the chiral AcONa derived from methionine with the ( S)-[D,T]methyl group ( F = 31.7) and ( R) for the one derived from methionine with the ( R)-[D,T]methyl group ( F = 83.0). The radical SAM methyltransferase transfers the methyl group of MeCbl to HEP-CMP with inversion of configuration.
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