The gusBC genes of Escherichia coli encode a glucuronide transport system.

Authors: Liang, W.-J., Wilson, K.J., Xie, H., Knol, J., Suzuki, S., Rutherford, N.G., Henderson, P.J.F. and Jefferson, R.A.

Journal: J Bacteriol

Volume: 187

Issue: 7

Pages: 2377-2385

ISSN: 0021-9193

DOI: 10.1128/JB.187.7.2377-2385.2005

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.

Source: PubMed

The gusBC Genes of Escherichia coli Encode a Glucuronide Transport System

Authors: Liang, W.-J., Wilson, K.J., Xie, H., Knol, J., Suzuki, S., Rutherford, N.G., Henderson, P.J. and Jefferson, R.A.

Journal: Journal of Bacteriology

Volume: 187

Pages: 2377-2385

ISSN: 0021-9193

DOI: 10.1128/JB.187.7.2377-2385.2005

Abstract:

Two genes, gusB and gusC, from a natural fecal isolate of Escherichia coli are shown to encode proteins responsible for transport of ß-glucuronides with synthetic [14C]phenyl-1-thio-ß-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 ß-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.

http://jb.asm.org/cgi/content/abstract/187/7/2377

Source: Manual

Preferred by: Wei-Jun Liang

The gusBC genes of Escherichia coli encode a glucuronide transport system.

Authors: Liang, W.-J., Wilson, K.J., Xie, H., Knol, J., Suzuki, S., Rutherford, N.G., Henderson, P.J.F. and Jefferson, R.A.

Journal: Journal of bacteriology

Volume: 187

Issue: 7

Pages: 2377-2385

eISSN: 1098-5530

ISSN: 0021-9193

DOI: 10.1128/jb.187.7.2377-2385.2005

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.

Source: Europe PubMed Central