Action at a distance for specific repression of the glpD and glpTQ genes, and organization of the glpEGR genes of Escherichia coli K-12

Aerobic sn-glycero13-phosphate (glycerol-P) dehydrogenase is a cytoplasmic membrane-associated respiratory enzyme encoded by the g/pD gene of Escherichia coli. The divergently transcribed glpACB and glpTQ operons encode the subunits of the anaerobic glycerol-P dehydrogenase, glycerol-P transporter, and glycerophosphodiesterase, respectively. The glpD operon is controlled by cooperative binding of glp repressor (GlpR) to tandem operators that cover the -10 promoter element and 30 bp downstream of the transcription start site. The glpACB-glpTQ operons operons are controlled by GlpR binding to operators that overlap the glpA promoter elements. In this study, two additional operators were identified within the glpD structural gene, and three additional operators were identified within the glp T structural gene.