Regulatory and molecular properties of citrate synthases from methylotrophs

Abstract

Gram-negative methylotrophs contain a high-Mr‘large’ citrate synthase. Gram-positive methylotrophs, on the other hand, contain a ‘small’ citrate synthase. These differences in Mr coincided partly with differences in NADH sensitivity. Citrate synthases from obligate Gram-negative and Gram-positive facultative methylotrophs were insensitive to feedback inhibition by NADH; only the enzymes from Gram-negative facultative methylotrophs were inhibited by NADH.