Phylogenetic analysis of the structure of RNase MRP RNA in yeasts
RNase MRP is a ribonucleoprotein enzyme involved in processing precursor rRNA in eukaryotes. To facilitate our structure–function analysis of RNase MRP from Saccharomyces cerevisiae, we have determined the likely secondary structure of the RNA component by a phylogenetic approach in which we sequenced all or part of the RNase MRP RNAs from 17 additional species of the Saccharomycetaceae family. The structure deduced from these sequences contains the helices previously suggested to be common to the RNA subunit of RNase MRP and the related RNA subunit of RNase P, an enzyme cleaving tRNA precursors. However, outside this common region, the structure of RNase MRP RNA determined here differs from a previously proposed universal structure for RNase MRPs. Chemical and enzymatic structure probing analyses were consistent with our revised secondary structure. Comparison of all known RNase MRP RNA sequences revealed three regions with highly conserved nucleotides. Two of these regions are part of a helix implicated in RNA catalysis in RNase P, suggesting that RNase MRP may cleave rRNA using a similar catalytic mechanism.(Received January 18 2002)
(Revised February 17 2002)
(Accepted March 29 2002)
Key Words: RNA catalysis; RNA processing; rRNA.
c1 Reprint requests to: Lasse Lindahl, Department of Biological Sciences, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA; e-mail: email@example.com.