Manganese ions induce miscleavage in the Escherichia coli RNase P RNA-catalyzed reaction
1999 (English)In: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 292, no 1, 53-63 p.Article in journal (Refereed) Published
Cleavage by the endoribonuclease RNase P requires the presence of divalent metal ions, of which Mg2+ promotes most efficient cleavage. Here we have studied the importance of there being Mg2+ in RNase P RNA catalysis. It is demonstrated that addition of Mn2+ resulted in a shift of the cleavage site and that this shift was associated with a change in the kinetic constants, in particular kcat. Our data further suggest that the influence of Mn2+ on cleavage site recognition depends on the -1/+73 base-pair in the substrate and the +73/294 base-pair in the RNase P RNA-substrate (RS)-complex. Based on our data we suggest that cleavage in the presence of Mg2+ as the only divalent metal ion proceeds through an intermediate which involves the establishment of the +73/294 base-pair in the RS-complex. By contrast, addition of Mn2+ favours an alternative pathway which results in a shift of the cleavage site. We also studied the influence of Mn2+ on cleavage site recognition and the kinetics of cleavage using various RNase P RNA derivatives carrying substitutions in the region of RNase P RNA that base-pair with the 3' terminal end of the substrate. From these results we conclude that a change in the structure of this RNase P RNA domain influences the involvement of a divalent metal ion(s) in the chemistry of cleavage.
Place, publisher, year, edition, pages
1999. Vol. 292, no 1, 53-63 p.
RNase P, catalytic RNA, ribozyme, divalent metal ions
IdentifiersURN: urn:nbn:se:uu:diva-147830DOI: 10.1006/jmbi.1999.3048ISI: 000082506400005PubMedID: 10493856OAI: oai:DiVA.org:uu-147830DiVA: diva2:400917