Repression of penicillin G acylase of Proteus rettgeri by tricarboxylic acid cycle intermediates.

The regulation of the penicillin acylase in proteus rettgeri ATCC 31052 was compared with that of the enzyme in Escherichia coli ATCC 9637. Unlike the E. coli acylase, the P. rettgeri enzyme was not induced by phenylacetic acid, nor was it subject to catabolite repression by glucose. The P. rettgeri acylase appears to be expressed constitutively but is subject to repression by the C4-dicarboxylic acids of the tricarboxylic acid cycle, succinate, fumarate, and malate.