Structure of Escherichia coli Hfq bound to polyriboadenylate RNA.

ABSTRACT: Hfq is a small, highly abundant hexameric protein that is found in many bacteria and plays a critical role in mRNA expression and RNA stability. As an "RNA chaperone," Hfq binds AU-rich sequences and facilitates the trans annealing of small RNAs (sRNAs) to their target mRNAs, typically resulting in the down-regulation of gene expression. Hfq also plays a key role in bacterial RNA decay by binding tightly to polyadenylate [poly(A)] tracts. The structural mechanism by which Hfq recognizes and binds poly(A) is unknown. Here, we report the crystal structure of Escherichia coli Hfq bound to the poly(A) RNA, A(15). The structure reveals a unique RNA binding mechanism. Unlike uridine-containing sequences, which bind to the "proximal" face, the poly(A) tract binds to the "distal" face of Hfq using

SUBMITTER: Link TM 

PROVIDER: S-EPMC2773200 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature