4.7.1.1 alpha-D-ribose 1-methylphosphonate 5-phosphate - 422762 4.7.1.1 alpha-D-ribose 1-methylphosphonate 5-phosphate the carbon-phosphorus bond of the substrate is cleaved via a radical-based reaction to alpha-D-ribose 1,2-cyclic-phosphate 5-phosphate and methane in the presence of S-adenosyl-L-methionine. Enzyme additionally requires S-adenosyl-L-methionine 422762