Ribonuclease P (Rnp) is a ubiquitous ribozyme that catalyzes a Mg2 -dependent hydrolysis to remove the 5'-leader sequence of precursor tRNA (pre-tRNA) in all three domains of life [ PUBMED:7731988 ]. In bacteria, the catalytic RNA (typically ~120kDa) is aided by a small protein cofactor (~14kDa) [ PUBMED:28971852 … expand

Ribonuclease P (Rnp) is a ubiquitous ribozyme that catalyzes a Mg2 -dependent hydrolysis to remove the 5'-leader sequence of precursor tRNA (pre-tRNA) in all three domains of life [ PUBMED:7731988 ]. In bacteria, the catalytic RNA (typically ~120kDa) is aided by a small protein cofactor (~14kDa) [ PUBMED:28971852 ]. Archaeal and eukaryote RNase P consist of a single RNA and archaeal RNase P has four or five proteins, while eukaryotic RNase P consists of 9 or 10 proteins. Eukaryotic and archaeal RNase P RNAs cooperatively function with protein subunits in catalysis [ PUBMED:10024167 ].

Eukaryotic nuclear RNase P shares most of its protein components with another essential RNP enzyme, nucleolar RNase MRP [ PUBMED:28971852 ]. RNase MRP (mitochondrial RNA processing) is an rRNA processing enzyme that cleaves various RNAs, including ribosomal, messenger, and mitochondrial RNAs. It can cleave a specific site within precursor rRNA to generate the mature 5'-end of 5.8S rRNA [ PUBMED:15916546 ]. Despite its name, the vast majority of RNase MRP is localized in the nucleolus [ PUBMED:20627997 ]. RNase MRP has been shown to cleave primers for mitochondrial DNA replication and CLB2 mRNA. In yeast, RNase MRP possesses one putatively catalytic RNA and at least 9 protein subunits (Pop1, Pop3-Pop8, Rpp1, Snm1 and Rmp1) [ PUBMED:21665995 ]. Human RNase MRP complex consists of 267 nucleotides and supports the interaction with and among at least seven protein components: hPop1, hPop5, Rpp20, Rpp25, Rpp30, Rpp38, and Rpp40) and three additional proteins, hPop4, Rpp21 and Rpp14, have been reported to be associated with at least a subset of RNase MRP complexes [ PUBMED:21956908 ].

This entry includes p29 subunit (also known as Rpp29 or Pop4) of the Ribonuclease P complex [ PUBMED:10352175 ]. Its homologues from eukaryotes are also a subunit of the RNase MRP complex. The structure of the RNase P subunit, Rpp29, from Methanobacterium thermoautotrophicum has been determined. Mth Rpp29 is a member of the oligonucleotide/oligosaccharide binding fold family. It contains a structured β-barrel core and unstructured N- and C-terminal extensions bearing several highly conserved amino acid residues that could be involved in RNA contacts in the protein-RNA complex [ PUBMED:14673079 ]. Rpp29 ( EC:3.1.26.5 ) catalyses the endonucleolytic cleavage of RNA, removing 5'-extranucleotides from tRNA precursor. It interacts with the Rpp25 and Pop5 subunits.