Regulation of magnesium homeostasis in Salmonella: Mg2+ targets the mgtA transcript for degradation by RNase E

SPINELLI, SILVANA V.; PONTEL, LUCAS B.; GARCíA VéSCOVI, ELEONORA; SONCINI, FERNANDO C.

FEMS MICROBIOLOGY LETTERS

WILEY-BLACKWELL PUBLISHING, INC

Año: 2008 vol. 280 p. 226 - 234

0378-1097

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