Mg2+ regulates transcription of mgtA in Salmonella Typhimurium via translation of proline codons during synthesis of the MgtL peptide.

ABSTRACT: In Salmonella enterica serovar Typhimurium, Mg²⁺ limitation induces transcription of the mgtA Mg²⁺ transport gene, but the mechanism involved is unclear. The 5' leader of the mgtA mRNA contains a 17-codon, proline-rich ORF, mgtL, whose translation regulates the transcription of mgtA [Park S-Y et al. (2010) Cell 142:737-748]. Rapid translation of mgtL promotes formation of a secondary structure in the mgtA mRNA that permits termination of transcription by the Rho protein upstream of mgtA, whereas slow or incomplete translation of mgtL generates a different structure that blocks termination. We identified the following mutations that conferred high-level transcription of mgtA at high [Mg²⁺]: (i) a base-pair change that introduced an additional proline codon i

SUBMITTER: Gall AR 

PROVIDER: S-EPMC5206563 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature