Hexose/Pentose and Hexitol/Pentitol Metabolism
- Authors: Christoph Mayer1, and Winfried Boos
- Editor: Valley Stewart2
VIEW AFFILIATIONS HIDE AFFILIATIONSAffiliations: 1: Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany; 2: University of California, Davis, Davis, CA
Received 08 December 2004 Accepted 10 January 2005 Published 29 March 2005
- Address correspondence to Christoph Mayer firstname.lastname@example.org
Escherichia coli and Salmonella enterica serovar Typhimurium exhibit a remarkable versatility in the usage of different sugars as the sole source of carbon and energy, reflecting their ability to make use of the digested meals of mammalia and of the ample offerings in the wild. Degradation of sugars starts with their energy-dependent uptake through the cytoplasmic membrane and is carried on further by specific enzymes in the cytoplasm, destined finally for degradation in central metabolic pathways. As variant as the different sugars are, the biochemical strategies to act on them are few. They include phosphorylation, keto-enol isomerization, oxido/reductions, and aldol cleavage. The catabolic repertoire for using carbohydrate sources is largely the same in E. coli and in serovar Typhimurium. Nonetheless, significant differences are found, even among the strains and substrains of each species. We have grouped the sugars to be discussed according to their first step in metabolism, which is their active transport, and follow their path to glycolysis, catalyzed by the sugar-specific enzymes. We will first discuss the phosphotransferase system (PTS) sugars, then the sugars transported by ATP-binding cassette (ABC) transporters, followed by those that are taken up via proton motive force (PMF)-dependent transporters. We have focused on the catabolism and pathway regulation of hexose and pentose monosaccharides as well as the corresponding sugar alcohols but have also included disaccharides and simple glycosides while excluding polysaccharide catabolism, except for maltodextrins.
Citation: Mayer C, Boos W. 2005. Hexose/Pentose and Hexitol/Pentitol Metabolism, EcoSal Plus 2005; doi:10.1128/ecosalplus.3.4.1