Evidence for induced fit in bacterial RNase P RNA-mediated cleavage
2007 (English)In: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 372, no 5, 1149-1164 p.Article in journal (Refereed) Published
RNase P with its catalytic RNA subunit is involved in the processing of a number of RNA precursors with different structures. However, precursor tRNAs are the most abundant substrates for RNase P. Available data suggest that a tRNA is folded into its characteristic structure already at the precursor state and that RNase P recognizes this structure. The tRNA D-/T-loop domain (TSL-region) is suggested to interact with the specificity domain of RNase P RNA while residues in the catalytic domain interact with the cleavage site. Here, we have studied the consequences of a productive interaction between the TSL-region and its binding site (TBS) in the specificity domain using tRNA precursors and various hairpin-loop model substrates. The different substrates were analyzed with respect to cleavage site recognition, ground-state binding, cleavage as a function of the concentration of Mg2+ and the rate of cleavage under conditions where chemistry is suggested to be rate limiting using wild-type Escherichia coli RNase P RNA, M1 RNA, and M1 RNA variants with structural changes in the TBS-region. On the basis of our data, we conclude that a productive TSL/TBS interaction results in a conformational change in the M1 RNA substrate complex that has an effect on catalysis. Moreover, it is likely that this conformational change comprises positioning of chemical groups (and Mg2+) at and in the vicinity of the cleavage site. Hence, our findings are consistent with an induced-fit mechanism in RNase P RNA-mediated cleavage.
Place, publisher, year, edition, pages
2007. Vol. 372, no 5, 1149-1164 p.
RNase P, ribozyme, divalent metal ions, tRNA precursors, tRNA processing
IdentifiersURN: urn:nbn:se:uu:diva-14904DOI: 10.1016/j.jmb.2007.07.030ISI: 000249817500003PubMedID: 17719605OAI: oai:DiVA.org:uu-14904DiVA: diva2:42675