Multimetabolite Control of a Biosynthetic Pathway by Sequential Metabolites

Synergistic control by two sequential metabolites of a biosynthetic pathway has been found to occur at an early stage of the biogenesis of methionine and S-adenosylmethionine in Escherichia coli. The enzyme is synergistically inhibited in a manner which indicates interaction at dual sites with the same enzyme, O-succinylhomoserine synthetase. Methionine and S-adenosylmethionine exert appreciable inhibitory effects alone only at high concentrations relative to the low concentrations required for inhibition by a combination of these metabolites.