Linkage of catalysis and 5' end recognition in ribonuclease RNase J
Jones, George H
Nucleic Acids Research
Oxford University Press
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Pei, X., Bralley, P., Jones, G. H., & Luisi, B. (2015). Linkage of catalysis and 5' end recognition in ribonuclease RNase J. Nucleic Acids Research, 43 8066-8076. https://doi.org/10.1093/nar/gkv732
In diverse bacterial species, the turnover and processing of many RNAs is mediated by the ribonuclease RNase J, a member of the widely occurring metallo-β-lactamase enzyme family. We present crystal structures of Streptomyces coelicolor RNase J with bound RNA in pre- and post-cleavage states, at 2.27 Å and 2.80 Å resolution, respectively. These structures reveal snapshots of the enzyme cleaving substrate directionally and sequentially from the 5′ terminus. In the pre-cleavage state, a water molecule is coordinated to a zinc ion pair in the active site but is imperfectly oriented to launch a nucleophilic attack on the phosphate backbone. A conformational switch is envisaged that enables the in-line positioning of the attacking water and may be facilitated by magnesium ions. Adjacent to the scissile bond, four bases are stacked in a tightly sandwiching pocket, and mutagenesis results indicate that this organization helps to drive processive exo-ribonucleolytic cleavage. Like its numerous homologues, S. coelicolor RNase J can also cleave some RNA internally, and the structural data suggest how the preference for exo- versus endo-cleavage mode is linked with recognition of the chemical status of the substrate's 5′ end.
B.F.L. and X.Y.P. are supported by the Wellcome Trust.
Wellcome Trust (076846/Z/05/A)
Wellcome Trust (076846/Z/05/B)
External DOI: https://doi.org/10.1093/nar/gkv732
This record's URL: https://www.repository.cam.ac.uk/handle/1810/250530