Titel
A multifunctional small RNA binding protein for sensing and signaling cell envelope precursor availability in bacteria
Autor*in
Abstract
Synthesis of glucosamine-6-phosphate (GlcN6P) by the enzyme GlmS initiates bacterial cell envelope biosynthesis. To ensure ongoing synthesis, GlcN6P homeostasis is required. Escherichia coli achieves this through a post-transcriptional control mechanism comprising the RNA-binding protein RapZ and small RNAs (sRNAs) GlmY and GlmZ. GlmZ stimulates glmS translation by base-pairing. When GlcN6P is abundant, GlmZ is cleaved and inactivated by endoribonuclease RNase E. Cleavage depends on RapZ, which binds GlmZ and recruits RNase E. Decreasing GlcN6P concentrations provoke up-regulation of the decoy sRNA GlmY which sequesters RapZ, thereby suppressing GlmZ decay. In our current study we identify RapZ as the GlcN6P sensor. GlcN6P-free RapZ interacts with and stimulates phosphorylation of the two-component system (TCS) QseE/QseF triggering glmY expression. Thereby generated GlmY sequesters RapZ into stable complexes, allowing for glmS expression. Sequestration by GlmY also disables RapZ to stimulate QseE/QseF, providing a negative feed-back loop limiting the response. When GlcN6P is replenished, GlmY is released from RapZ and rapidly degraded. Our work has revealed a complex regulatory scenario, in which an RNA binding protein senses a metabolite and communicates with two sRNAs, a TCS and ribonuclease RNase E to achieve metabolite homeostasis.
Stichwort
RNA binding proteinmetabolite sensingsmall regulatory RNAtwo-component systemcell envelope precursorEscherichia coli
Objekt-Typ
Sprache
Englisch [eng]
Persistent identifier
Erschienen in
Titel
Microbial Cell
Band
7
Ausgabe
5
ISSN
2311-2638
Erscheinungsdatum
2020
Seitenanfang
139
Seitenende
142
Publication
Shared Science Publishers OG
Erscheinungsdatum
2020
Zugänglichkeit
Rechte
Rechteangabe
© 2020 Khan and Görke
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