High-level, constitutive expression of the mgtC gene confers increased thermotolerance on Salmonella enterica serovar Typhimurium.

Autor: Gall AR; Department of Biological Sciences, Purdue University., Hegarty AE; Department of Biological Sciences, Purdue University., Datsenko KA; Department of Biological Sciences, Purdue University., Westerman RP; Purdue University Genomics Core, West Lafayette, IN, 47907, USA., SanMiguel P; Purdue University Genomics Core, West Lafayette, IN, 47907, USA., Csonka LN; Department of Biological Sciences, Purdue University.
Jazyk: angličtina
Zdroj: Molecular microbiology [Mol Microbiol] 2018 Aug; Vol. 109 (3), pp. 327-344. Date of Electronic Publication: 2018 Jul 31.
DOI: 10.1111/mmi.13988
Abstrakt: We found that mutations that increased the transcription of the mgtCBR (Mg 2+ transport-related) operon conferred increased thermotolerance on this organism. The 5' leader of the mgtCBR mRNA contains two short open reading frames (ORFs), mgtM and mgtP, whose translation regulates the expression of the mgtCBR operon by a mechanism that is similar to attenuation in amino acid biosynthetic operons. We obtained two types of mutations that resulted in elevated transcription of the operon: defects in the mgtM ribosome-binding site, impairing the translation of this ORF and deletions encompassing the stop codon of mgtM that extend the translation of this ORF across a downstream Rho termination site. These mgtM mutations give further insights into the mechanism of the transcriptional control of the mgtCBR operon that we discuss in this work. We show that the increased thermotolerance requires elevated expression of the mgtC gene, but functional mgtB and mgtR, which respectively encode an Mg 2+ transporter and a regulatory protein, are dispensable for this response. MgtC has been shown to have complex functions, including a requirement for virulence, flagella-independent motility and synthesis of cellulose and we now found that it has a role in the regulation of thermotolerance.
(© 2018 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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