Effect of replacing the general energy-coupling proteins of the PEP:sugar phosphotransferase system of Salmonella typhimurium with their fructose-inducible counterparts on utilization of the PTS sugar glucitol

• Published in: Microbiology (Society for General Microbiology) Vol. 148; no. 12; pp. 3857 - 3864
• Main Authors: Sutrina, Sarah L, Alleyne, Lisa, Hoyte, Keisher, Blenman, Margot
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-12-2002; Society for General Microbiology
• Subjects: Acetylglucosamine; Bacterial Proteins; Bacteriology; Biological and medical sciences; Carrier Proteins - genetics; Carrier Proteins - metabolism; Culture Media; Cyclic AMP - metabolism; Enzyme I; Escherichia coli Proteins; Fructose - metabolism; fructose repressor protein; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Genetics; glucitol; HPr protein; Intracellular Signaling Peptides and Proteins; melibiose; Metabolism. Enzymes; Microbiology; Mutation; Phosphoenolpyruvate Sugar Phosphotransferase System - genetics; Phosphoenolpyruvate Sugar Phosphotransferase System - metabolism; phosphoenolpyruvate:sugar phosphotransferase system; Phosphotransferases (Nitrogenous Group Acceptor) - genetics; Phosphotransferases (Nitrogenous Group Acceptor) - metabolism; Salmonella typhimurium; Salmonella typhimurium - enzymology; Salmonella typhimurium - growth & development; Sorbitol - metabolism; Sorbitol; Microorganism growth; Enzyme; Transferases; Site directed mutagenesis; Cyclic AMP; Glycerol; Salmonella typhimurium; Fructose; Isomerases; Mannitol; Intramolecular transferases; Bacteria; Phosphoenolpyruvate-protein phosphotransferase; Phosphotransferases; Enterobacteriaceae
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-148-12-3857

Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Barbados 1
Author for correspondence: Sarah L. Sutrina. Tel: [phone]. Fax: [phone]. e-mail: ssutrina{at}uwichill.edu.bb
A strain of Salmonella typhimurium in which the genes encoding the general phosphoenolpyruvate:sugar phosphotransferase system (PTS) proteins HPr and Enzyme I have been deleted, the normally cryptic gene encoding the fructose-inducible Enzyme I (EI* or EI fructose ) is expressed, and the fructose repressor protein is inactive ( fruR or cra mutant) was studied. This strain lacks HPr and EI, but expresses FPr (DTP) and EI fructose constitutively. Since FPr and EI fructose can substitute for HPr and EI, the strain grew in minimal liquid medium supplemented with the PTS sugars glucose, fructose, N- acetylglucosamine, mannitol or mannose. However, it showed very poor to negligible growth on the PTS sugar glucitol. It also grew very poorly on the non-PTS sugars maltose, melibiose and especially glycerol. Adding cAMP to the medium allowed growth on glucitol, but did not affect growth on glycerol. We suggest that poor phosphorylation of the regulatory molecule Enzyme IIA glucose by FPr is responsible for these effects.
Keywords: phosphoenolpyruvate:sugar phosphotransferase system, carbon catabolite control, gene regulation, carbohydrate transport Abbreviations: CAP, catabolite activator protein; DTP, diphosphoryltransfer protein; EI/EII, enzymes I/II; Fru, fructose; Glc, glucose; GlcNAc, N- acetylglucosamine; Gut, glucitol; Mtl, mannitol; PEP, phosphoenolpyruvate; PTS, phosphotransferase system