In the methionine biosynthesis reaction, the 5-methyl group from 5-methyltetrahydrofolate ends up on methionine, with overall retention of stereochemical configuration about the methyl carbon (this ca...In the methionine biosynthesis reaction, the 5-methyl group from 5-methyltetrahydrofolate ends up on methionine, with overall retention of stereochemical configuration about the methyl carbon (this can be demonstrated by using 2 H- and 3 H-labels on the methyl group- see section 9.1A).. Propose a likely mechanism for this process, taking into account the stereochemical outcome (you will need to infer the precursor to methionine).
