Maltose/Maltodextrin System of Escherichia coli : Transport, Metabolism, and Regulation

作者：Winfried Boos, Howard A. Shuman · 发表于：Microbiology and Molecular Biology Reviews · 年份：1998 · DOI：10.1128/mmbr.62.1.204-229.1998 · 被引用次数：633 · 研究领域：Bacterial Genetics and Biotechnology、Bacteriophages and microbial interactions、Enzyme Structure and Function

The maltose system of Escherichia coli offers an unusually rich set of enzymes, transporters, and regulators as objects of study. This system is responsible for the uptake and metabolism of glucose polymers (maltodextrins), which must be a preferred class of nutrients for E. coli in both mammalian hosts and in the environment. Because the metabolism of glucose polymers must be coordinated with both the anabolic and catabolic uses of glucose and glycogen, an intricate set of regulatory mechanisms controls the expression of mal genes, the activity of the maltose transporter, and the activities of the maltose/maltodextrin catabolic enzymes. The ease of isolating many of the mal gene products has contributed greatly to the understanding of the structures and functions of several classes of proteins. Not only was the outer membrane maltoporin, LamB, or the phage lambda receptor, the first virus receptor to be isolated, but also its three-dimensional structure, together with extensive knowledge of functional sites for ligand binding as well as for phage lambda binding, has led to a relatively complete description of this sugar-specific aqueous channel. The periplasmic maltose binding protein (MBP) has been studied with respect to its role in both maltose transport and maltose taxis. Again, the combination of structural and functional information has led to a significant understanding of how this soluble receptor participates in signaling the presence of sugar to the chemosensory ap...