RT Journal Article
SR Electronic
T1 RNA binding of Hfq monomers promotes RelA-mediated hexamerization in a limiting Hfq environment
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.08.11.244277
DO 10.1101/2020.08.11.244277
A1 Pallabi Basu
A1 Maya Elgrably-Weiss
A1 Fouad Hassouna
A1 Manoj Kumar
A1 Reuven Wiener
A1 Shoshy Altuvia
YR 2020
UL http://biorxiv.org/content/early/2020/08/11/2020.08.11.244277.abstract
AB The RNA chaperone Hfq acting as a hexamer, is a known mediator of post-transcriptional regulation expediting basepairing between small RNAs (sRNAs) and their target mRNAs. However, the intricate details associated with Hfq-RNA biogenesis are still unclear. Previously, we reported that the stringent response regulator, RelA is a functional partner of Hfq that facilitates Hfq-mediated sRNA-mRNA regulation in vivo and induces Hfq hexamerization in vitro. Here, for the first time we show that RelA-mediated Hfq hexamerization requires an initial binding of RNA, preferably sRNA to Hfq monomers. By interacting with a Shine-Dalgarno-like sequence (GGAG) in the sRNA, RelA stabilizes the initially unstable complex of RNA bound-Hfq monomer, enabling the attachment of more Hfq subunits to form a functional hexamer. Overall, our study showing that RNA binding to Hfq monomers is at the heart of RelA-mediated Hfq hexamerization, challenges the previous concept that only Hfq hexamers can bind RNA.Competing Interest StatementThe authors have declared no competing interest.