Larson, Timothy J.; Ehrmann, Michael; Boos, Winfried:
Periplasmic glycerophosphodiester phosphodiesterase of Escherichia coli, a new enzyme of the glp regulon
1983
In: Journal of Biological Chemistry, Jg. 258 (1983), Heft 9, S. 5428 - 5432
Artikel/Aufsatz in Zeitschrift / Fach: Biologie
Fakultät für Biologie
Titel:
Periplasmic glycerophosphodiester phosphodiesterase of Escherichia coli, a new enzyme of the glp regulon
Autor(in):
Larson, Timothy J.; Ehrmann, Michael im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen; Boos, Winfried
Erscheinungsjahr
1983
Erschienen in:
Journal of Biological Chemistry, Jg. 258 (1983), Heft 9, S. 5428 - 5432
ISSN
Signatur der UB
WWW URL

Abstract:

The promoter-proximal gene (glpT) of the glpT-glpQ operon of E. coli encodes a membrane permease responsible for active transport of sn-glycerol 3-phosphate. Promoter-distal glpQ encodes a periplasmic protein which is not required for active transport of sn-glycerol 3-phosphate. This periplasmic protein has now been identified as a phosphodiesterase which hydrolyzes glycerophosphodiesters into sn-glycerol 3-phosphate plus alcohol. The enzyme exhibited broad substrate specificity with respect to the alcohol moiety; sn-glycerol 3-phosphate was released from glycerophosphoethanolamine, glycerophosphocholine, glycerophosphoglycerol, and bis(glycerophospho)glycerol. The enzyme was specific for glycerophosphodiesters; bis(p-nitrophenyl)phosphate, a substrate for other phosphodiesterases, was not hydrolyzed. In a coupled spectrophotometric assay utilizing sn-glycerol 3-phosphate dehydrogenase and NAD, apparent activity was optimal at pH 9 and was stimulated by Ca2+. The substrates of the phosphodiesterase had no affinity for the glpT-encoded active transport system. Thus, the glpQ gene product expands the catabolic capability of the glp regulon to include a variety of glycerophosphodiesters.