RNAs actively cycle on the Sm-like protein Hfq

• Hfq, a protein required for small RNA (sRNA)-mediated regulation in bacteria, binds RNA with low-nanomolar K-d values and long half-lives of complexes (>100 min). This cannot be reconciled with the 1-2-min response time of regulation in vivo. We show that RNAs displace each other on Hfq on a short time scale by RNA concentration-driven (active) cycling. Already at submicromolar concentrations of competitor RNA, half-lives of RNA-Hfq complexes are approximate to 1 min. We propose that competitor RNA associates transiently with RNA-Hfq complexes, RNAs exchange binding sites, and one of the RNAs eventually dissociates. This solves the "strong binding-high turn-over" paradox and permits efficient use of the Hfq pool.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

Hfq

sRNA

antisense RNA

post-transcriptional regulation

RNA chaperone

Lsm protein

Biology

Biologi

Publikations- och innehållstyp

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