PMID:15774881

From EcoliWiki
Jump to: navigation, search
Citation

Liang, WJ, Wilson, KJ, Xie, H, Knol, J, Suzuki, S, Rutherford, NG, Henderson, PJ and Jefferson, RA (2005) The gusBC genes of Escherichia coli encode a glucuronide transport system. J. Bacteriol. 187:2377-85

Abstract

Two genes, gusB and gusC, from a natural fecal isolate of Escherichia coli are shown to encode proteins responsible for transport of beta-glucuronides with synthetic [(14)C]phenyl-1-thio-beta-d-glucuronide as the substrate. These genes are located in the gus operon downstream of the gusA gene on the E. coli genome, and their expression is induced by a variety of beta-d-glucuronides. Measurements of transport in right-side-out subcellular vesicles show the system has the characteristics of secondary active transport energized by the respiration-generated proton motive force. When the genes were cloned together downstream of the tac operator-promoter in the plasmid pTTQ18 expression vector, transport activity was increased considerably with isopropylthiogalactopyranoside as the inducer. Amplified expression of the GusB and GusC proteins enabled visualization and identification by N-terminal sequencing of both proteins, which migrated at ca. 32 kDa and 44 kDa, respectively. Separate expression of the GusB protein showed that it is essential for glucuronide transport and is located in the inner membrane, while the GusC protein does not catalyze transport but assists in an as yet unknown manner and is located in the outer membrane. The output of glucuronides as waste by mammals and uptake for nutrition by gut bacteria or reabsorption by the mammalian host is discussed.

Links

PubMed PMC1065211 Online version:10.1128/JB.187.7.2377-2385.2005

Keywords

Amino Acid Sequence; Biological Transport/genetics; Biological Transport/physiology; Chromosome Mapping; Escherichia coli/genetics; Escherichia coli/metabolism; Escherichia coli Proteins/genetics; Escherichia coli Proteins/metabolism; Glucuronides/metabolism; Membrane Transport Proteins/genetics; Membrane Transport Proteins/metabolism; Molecular Sequence Data; Promoter Regions, Genetic

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.