GENETIC CONTROL OF L-ALPHA-GLYCEROPHOSPHATE SYSTEM IN ESCHERICHIA COLI

Glycerol kinase, the l-α-glycerophosphate transport system and l-α-glycerophosphate dehydrogenase together constitute a converging pathway for the dissimilation of exogenous glycerol and l-α-glycerophosphate by Escherichia coli. The three functional units are coded by genes widely separated on the chromosome. These three operons are under the control of a single regulator gene which appears to be contiguous to the structural gene for the dehydrogenase. Specific repression is lifted by l-α-glycerophosphate, which does not have to be further catabolized for its inducer activity. Mutations in the regulator gene can lead to constitutivity, non-inducibility, or temperature-sensitive control. Deletions in this gene result in derepression of all three operons. Thus the l-α-glycerophosphate system is a regulon under negative control. © 1968.