Functional Coupling between a Distal Interaction and the Cleavage Site in Bacterial RNase-P-RNA-Mediated Cleavage
2011 (English)In: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 411, no 2, 384-396 p.Article in journal (Refereed) Published
Bacterial RNase P consists of one protein and one RNA [RNase P RNA (RPR)]. RPR can process tRNA precursors correctly in the absence of the protein. Here we have used model hairpin loop substrates corresponding to the acceptor, T-stem, and T-loop of a precursor tRNA to study the importance of the T-loop structure in RPR-alone reaction. T-stem/loop (TSL) interacts with a region in RPR [TSL binding site (TBS)], forming TSL/TBS interaction. Altering the T-loop structure affects both cleavage site selection and rate of cleavage at the correct site +1 and at the alternative site -1. The magnitude of variation depended on the structures of the T-loop and the TBS region, with as much as a 150-fold reduction in the rate of cleavage at +1. Interestingly, for one T-loop structure mutant, no difference in the rate at -1 was detected compared to cleavage of the substrate with an unchanged T-loop, indicating that, in this case, the altered T-loop structure primarily influences events required for efficient cleavage at the correct site +1. We also provide data supporting a functional link between a productive TSL/TBS interaction and events at the cleavage site. Collectively, our findings emphasize the interplay between separate regions upon formation of a productive RPR substrate that leads to efficient and accurate cleavage. These new data provide support for an induced-fit mechanism in bacterial RPR-mediated cleavage at the correct site +1.
Place, publisher, year, edition, pages
2011. Vol. 411, no 2, 384-396 p.
RNase P, ribozyme, divalent metal ions, tRNA precursors, tRNA processing
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:uu:diva-158314DOI: 10.1016/j.jmb.2011.05.049ISI: 000293938400007OAI: oai:DiVA.org:uu-158314DiVA: diva2:439106