Deficiency of a Sinorhizobium meliloti bacA Mutant in Alfalfa Symbiosis Correlates with Alteration of the Cell Envelope

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Gail P. Ferguson (Creator)

R. Martin II Roop (Creator)

Graham C. Walker (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: The BacA protein is essential for the long-term survival of Sinorhizobium meliloti and Brucella abortus within acidic compartments in plant and animal cells respectively. Since both the S. meliloti and B. abortus bacA mutants have an increased resistance to bleomycin it was hypothesized that BacA was a transporter of bleomycin and bleomycin-like compounds into the bacterial cell. However our finding that the S. meliloti bacA mutant also has an increased sensitivity to detergents a hydrophobic dye ethanol and acid pH supported a model in which BacA function affects the bacterial cell envelope. In addition an S. meliloti lpsB mutant that is defective at a stage in infection of the host similar to that found for a bacA mutant is also sensitive to the same agents and the carbohydrate content of its lipopolysaccharide (LPS) is altered. However analysis of crude preparations of the bacA mutant LPS suggested that unlike that for LpsB BacA function did not affect the carbohydrate composition of the LPS. Rather we found that at least one function of BacA is to affect the distribution of LPS fatty acids including a very-long-chain fatty acid thought to be unique to the alpha-proteobacteria including B. abortus. Originally published Journal of Bacteriology Vol. 184 No. 20 Oct 2002

Additional Information

Publication

Other

Journal of Bacteriology. 184:20(October 2002) p. 5625-5632.

Language: English

Date: 2011

Keywords

BacA protein, bacterial cell envelope, LPS fatty acids

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