HflX is a ribosome-splitting factor rescuing stalled ribosomes under stress conditions
2015 (English)In: Nature Structural & Molecular Biology, ISSN 1545-9993, E-ISSN 1545-9985, Vol. 22, no 11, 906-913 p.Article in journal (Refereed) Published
Adverse cellular conditions often lead to nonproductive translational stalling and arrest of ribosomes on mRNAs. Here, we used fast kinetics and cryo-EM to characterize Escherichia coil HflX, a GTPase with unknown function. Our data reveal that HflX is a heat shock-induced ribosome-splitting factor capable of dissociating vacant as well as mRNA-associated ribosomes with deacylated tRNA in the peptidyl site. Structural data demonstrate that the N-terminal effector domain of HflX binds to the peptidyl transferase center in a strikingly similar manner as that of the class I release factors and induces dramatic conformational changes in central intersubunit bridges, thus promoting subunit dissociation. Accordingly, loss of HflX results in an increase in stalled ribosomes upon heat shock, These results suggest a primary role of HflX in rescuing translationally arrested ribosomes under stress conditions.
Place, publisher, year, edition, pages
2015. Vol. 22, no 11, 906-913 p.
IdentifiersURN: urn:nbn:se:uu:diva-268420DOI: 10.1038/nsmb.3103ISI: 000364273800014PubMedID: 26458047OAI: oai:DiVA.org:uu-268420DiVA: diva2:877200
FunderSwedish Research Council, 2010-2619Swedish Research Council, 2011-6088Swedish Research Council, 2014-4423Swedish Research Council, 2008-6593Knut and Alice Wallenberg Foundation, KAW 2011.0081