Catabolite modulator factor: a possible mediator of catabolite repression in bacteria.

Abstract
Water soluble extracts of Escherichia coli cells exerted an extremely strong repressive effect upon the expression of catabolite sensitive operons. The compound responsible for this activity was partially purified, had a low molecular weight and was heat stable. The effect of this compound, designated as catabolite modulator factor, is only partially antagonized by cyclic AMP. The possible role of catabolite modulator factor in the physiological regulation of catabolite repression is discussed.