2.5.1.6 ATP + L-methionine + H2O = phosphate + diphosphate + S-adenosyl-L-methionine catalysis of a SN2 reaction through hydrogen bonding of the liberated oxygen-5' to the histidine, charge neutralization by the two Mg2+ ions, and stabilization of the product sulfonium cation through a close, non-bonded, contact between the sulfur and the ribose oxygen-4' 701932 2.5.1.6 ATP + L-methionine + H2O = phosphate + diphosphate + S-adenosyl-L-methionine mechanism 639038 2.5.1.6 ATP + L-methionine + H2O = phosphate + diphosphate + S-adenosyl-L-methionine mechanism of inhibiton by product analogues and implications for reaction 658062 2.5.1.6 ATP + L-methionine + H2O = phosphate + diphosphate + S-adenosyl-L-methionine mechanism, key role of K182 in the correct positioning of the substrates, and D135 in stabilizing the sulfonium group formed in the product 659701 2.5.1.6 ATP + L-methionine + H2O = phosphate + diphosphate + S-adenosyl-L-methionine neutral H14 acts as an acid to cleave the C5’-O5’ bond of ATP, S of methionine makes a nucleophilic attack on the C5’ to form the product 658053 2.5.1.6 ATP + L-methionine + H2O = phosphate + diphosphate + S-adenosyl-L-methionine steady state ordered Bi Ter mechanism with ATP adding before L-methionine and S-adenosylmethionine being the first product released, random release of phosphate and diphosphate 639052