The low-resolution solution structure ofVibrio choleraeHfq in complex with Qrr1 sRNA.
InVibrio cholerae, the RNA binding protein and chaperone Hfq (VcHfq) facilitates the pairing of the quorum regulatory RNA (Qrr) small regulatory RNAs (sRNAs) to the 5' untranslated regions of the mRNAs for a number of global regulators that modulate the expression of virulence genes. This Qrr-mediated sRNA circuit is an attractive antimicrobial target, but characterization at the molecular level is required for this to be realized. Here, we investigate the interactions between VcHfq and the Qrr sRNAs using a variety of biochemical and biophysical techniques. We show that the ring-shaped VcHfq hexamer binds the Qrrs with 1:1 stoichiometry through its proximal face, and the molecular envelope of the VcHfq-Qrr complex is experimentally determined from small angle scattering data to present the first structural glimpse of a Hfq-sRNA complex. This structure reveals that the VcHfq protein does not change shape on complex formation but the RNA does, suggesting that a chaperone role for VcHfq is a critical part of the VcHfq-Qrr interaction. Overall, these studies enhance our understanding of VcHfq-Qrr interactions.
Biophysics Laboratories, School of Biological Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, PO1 2DT, UK.
Helen A
HA
Vincent
Charlotte A
CA
Henderson
Carlanne M
CM
Stone
Peter D
PD
Cary
Darren M
DM
Gowers
Frank
F
Sobott
James E N
JEN
Taylor
Anastasia J
AJ
Callaghan
D001665:Binding Sites; D035001:Host Factor 1 Protein / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D058727:RNA, Small Untranslated / Q000737:chemistry* / Q000378:metabolism; D053838:Scattering, Small Angle; D014734:Vibrio cholerae
D035001:Host Factor 1 Protein; D058727:RNA, Small Untranslated