2.1.1.308	2 S-adenosyl-L-methionine + cytidine 5'-{[hydroxy(2-hydroxyethyl)phosphonoyl]phosphate} + reduced acceptor = S-adenosyl-L-homocysteine + 5'-deoxyadenosine + L-methionine + cytidine 5'-{[hydroxy(2-hydroxypropyl)phosphonoyl]phosphate} + oxidized acceptor	proposed mechanism: a 5'-deoxyadenosine radical generated from reductive cleavage of S-adenosyl-L-methionine is used to abstract the hydrogen atom from the C-H bond of the substrate resulting in a substrate radical that reacts with methylcobalamin yielding (S)-2-hydroxypropylphosphonate and cob(II)alamin	703345	
2.1.1.308	2 S-adenosyl-L-methionine + cytidine 5'-{[hydroxy(2-hydroxyethyl)phosphonoyl]phosphate} + reduced acceptor = S-adenosyl-L-homocysteine + 5'-deoxyadenosine + L-methionine + cytidine 5'-{[hydroxy(2-hydroxypropyl)phosphonoyl]phosphate} + oxidized acceptor	proposed mechanism: one electron is transferred from the reduced iron–sulfur cluster to S-adenosyl-L-methionine to form an adenosyl radical and methionine. The adenosyl radical abstracts the pro-R hydrogen atom from C2 of (S)-2-hydroxyethylphosphonate, and the resulting substrate radical reacts with methylcobalamin yielding (S)-2-hydroxypropylphosphonate and cob(II)alamin. The enzyme is then returned to the active state by reduction of the 4Fe4S cluster back to the +1 state and binding of S-adenosyl-L-methionine and methylcobalamin. Alternatively, cob(II)alamin might be reduced to cob(I)alamin and methylated while bound to the enzyme	703183