Characterization of a Snorhizobium meliloti ATP-binding cassette histidine transporter also involved in betaine and proline uptake.

ABSTRACT: The symbiotic soil bacterium Sinorhizobium meliloti uses the compatible solutes glycine betaine and proline betaine for both protection against osmotic stress and, at low osmolarities, as an energy source. A PCR strategy based on conserved domains in components of the glycine betaine uptake systems from Escherichia coli (ProU) and Bacillus subtilis (OpuA and OpuC) allowed us to identify a highly homologous ATP-binding cassette (ABC) binding protein-dependent transporter in S. meliloti. This system was encoded by three genes (hutXWV) of an operon which also contained a fourth gene (hutH2) encoding a putative histidase, which is an enzyme involved in the first step of histidine catabolism. Site-directed mutagenesis of the gene encoding the periplasmic binding protein (hutX) and of the gene e

SUBMITTER: Boncompagni E 

PROVIDER: S-EPMC94542 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature