Regulation of Magnesium Homeostasis in Salmonella: Mg(2+) Targets the mgtA Transcript for Degradation by RNase E

FEMS Microbiol Lett. 2008 Mar;280(2):226-34. doi: 10.1111/j.1574-6968.2008.01065.x. Epub 2008 Feb 4.


Extracellular Mg(2+) controls the activation of the Salmonella PhoP/PhoQ regulatory system. One of the adaptive responses driven by PhoP/PhoQ includes the transcriptional induction of mgtA and mgtCB, which encode two P-type Mg(2+) transporters. Mg(2+) also controls mgtA expression by a riboswitch located in its 5'-untranslated region (5'UTR). In this work, it was shown that the 5'UTR of both mgtA and mgtCB is responsible for a fine-tuned Mg(2+)-dependent regulation of these genes. Evidence was also provided that the Mg(2+) riboswitch targets the mgtA transcript for degradation by RNase E when cells are grown in high Mg(2+) environments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5' Untranslated Regions
  • Adenosine Triphosphatases / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Cation Transport Proteins
  • Endoribonucleases / metabolism*
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial / drug effects
  • Homeostasis*
  • Magnesium / metabolism
  • Magnesium / pharmacology*
  • Membrane Transport Proteins / metabolism*
  • Salmonella / genetics
  • Salmonella / growth & development
  • Salmonella / metabolism*
  • Transcription, Genetic


  • 5' Untranslated Regions
  • Bacterial Proteins
  • Cation Transport Proteins
  • Escherichia coli Proteins
  • Membrane Transport Proteins
  • Endoribonucleases
  • ribonuclease E
  • Adenosine Triphosphatases
  • MgtA protein, E coli
  • MgtB protein, Salmonella typhimurium
  • MgtC protein, Salmonella typhimurium
  • Magnesium