Analysis of the exochelin locus in Mycobacterium smegmatis: biosynthesis genes have homology with genes of the peptide synthetase family.

ABSTRACT: Mycobacteria secrete the siderophore exochelin when grown under iron-limiting conditions. In order to understand iron uptake mechanisms in mycobacteria, we have taken a genetic approach to identify those genes involved in exochelin biosynthesis and transport in Mycobacterium smegmatis. Of the 6,000 chemically mutagenized clones of M. smegmatis mc2155 screened on agar plates containing chrome azural S, 19 mutants that had lost the ability to produce or secrete exochelin were identified. Thirteen of these mutants were complemented by a single M. smegmatis cosmid. Sequence analysis of this cosmid revealed nine open reading frames, three of which are homologous to genes encoding transporter proteins, which are likely involved in exochelin transport. Complementation and Tn10 mutagenesis analysi

SUBMITTER: Yu S 

PROVIDER: S-EPMC107483 | biostudies-literature | 1998 Sep

REPOSITORIES: biostudies-literature