Identification of rhtX and fptX, novel genes encoding proteins that show homology and function in the utilization of the siderophores rhizobactin 1021 by Sinorhizobium meliloti and pyochelin by Pseudomonas aeruginosa, respectively.

ABSTRACT: Rhizobactin 1021 is a hydroxymate siderophore produced by the soil bacterium Sinorhizobium meliloti 2011. A regulon comprising rhtA, encoding the outer membrane receptor protein for the ferrisiderophore; the biosynthesis operon rhbABCDEF; and rhrA, the Ara-C-like regulator of the receptor and biosynthesis genes has been previously described. We report the discovery of a gene, located upstream of rhbA and named rhtX (for "rhizobactin transport"), which is required, in addition to rhtA, to confer the ability to utilize rhizobactin 1021 on a strain of S. meliloti that does not naturally utilize the siderophore. Rhizobactin 1021 is structurally similar to aerobactin, which is transported in Escherichia coli via the IutA outer membrane receptor and the FhuCDB inner membrane transport system. E.

SUBMITTER: Cuiv PO 

PROVIDER: S-EPMC400637 | biostudies-literature | 2004 May

REPOSITORIES: biostudies-literature