The TonB, ExbB, and ExbD Proteins

Le résumé fourni par la source

The proton motive force (PMF) of the cytoplasmic membrane is harnessed as the energy source. This spatial separation of the energy source from the energy sink necessitates an intermediate linkage between the two processes. That function is fulfilled by three proteins, TonB, ExbB, and ExbD, that couple the cytoplasmic membrane PMF to the active transport of nutrients through outer membrane transporters. This chapter focuses on our current understanding of the means by which energy is harvested at the cytoplasmic membrane and delivered to the outer membrane transporters in Escherichia coli, and then reviews some of the diversity in this system that has recently become apparent. Based on evidence to date, it is reasonable to consider TonB to consist of three distinct functional domains: the amino-terminal domain, the central domain, and the carboxy-terminal domain. The ability of cells to transport cobalamin and various iron-siderophore complexes and their susceptibility to killing by bacteriophages and colicins are routinely used in assays to characterize phenotypes of mutant proteins in the TonB-dependent energy transduction system.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.