ID   2.1.1.308
DE   cytidylyl-2-hydroxyethylphosphonate methyltransferase.
CA   AH2 + cytidine 5'-{[hydroxy(2-hydroxyethyl)phosphonoyl]phosphate} +
CA   2 S-adenosyl-L-methionine = 5'-deoxyadenosine + A + cytidine
CA   5'-({hydroxy[(S)-2-hydroxypropyl]phosphonoyl}phosphate) + 2 H(+) +
CA   L-methionine + S-adenosyl-L-homocysteine.
CC   -!- Requires cobalamin.
CC   -!- The enzyme, isolated from the bacterium Streptomyces wedmorensis,
CC       is involved in fosfomycin biosynthesis.
CC   -!- It is a radical S-adenosyl-L-methionine (SAM) enzyme that contains a
CC       [4Fe-4S] center and a methylcob(III)alamin cofactor.
CC   -!- The enzyme uses two molecues of SAM for the reaction.
CC   -!- One molecule forms a 5'-deoxyadenosyl radical, while the other is
CC       used to methylate the cobalamin cofactor.
CC   -!- The 5'-deoxyadenosyl radical abstracts a hydrogen from the C2
CC       position of cytidine 5'-{[(2-hydroxyethyl)phosphonoyl]phosphate}
CC       forming a free radical that reacts with the methyl group on
CC       methylcob(III)alamin at the opposite side from SAM and the [4Fe-4S]
CC       cluster with inversion of configuration to produce the (S)-isomer of
CC       the methylated product and cob(II)alamin.
CC   -!- Both the [4Fe-4S] cluster and the cob(II)alamin need to be reduced by
CC       an unknown factor(s) before the enzyme could catalyze another cycle.
DR   Q56184, FOM3_STRWE ;
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