| Primary Identifier | IPR038085 | Type | Homologous_superfamily |
| Short Name | Rnp2-like_sf |
| description | This superfamily contains ribonuclease P (Rnp) proteins from eukaryotes and archaea. Rnp is a ubiquitous ribozyme that catalyzes a Mg2+-dependent hydrolysis to remove the 5'-leader sequence of precursor tRNA (pre-tRNA) []. 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 []. Eukaryotic nuclear RNase P shares most of its protein components with another essential RNP enzyme, nucleolar RNase MRP []. RNase MRP (mitochondrial RNA processing) is an rRNA processing enzyme that cleaves a specific site within precursor rRNA to generate the mature 5'-end of 5.8S rRNA []. Despite its name, the vast majority of RNase MRP is localized in the nucleolus []. 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) [].Human RNase P is composed of a singular protein Pop1 and three subcomplexes, the Rpp20-Rpp25 heterodimer, Pop5-Rpp14-(Rpp30)2-Rpp40 heteropentamer, and Rpp21-Rpp29-Rpp38 heterotrimer [].In the hyperthermophilic archaeon Pyrococcus horikoshii OT3, RNase P is composed of the RNase P RNA (pRNA) and five proteins (PhoPop5, PhoRpp38, PhoRpp21, PhoRpp29, and PhoRpp30) [, ].Proteins in this entry include Rnp2 (also known as Pop5) from archaea and Pop5/Rpp14 from humans. In eukaryotes Pop5 is a subunit of both the Rnp and MRP complexes. Although both Pop5 and Rpp14 have similar protein structure, they share a very limited sequence similarity. Moreover, the C-terminal fragments after the conserved beta sheets in Pop5 and Rpp14 exhibit distinct structural features that mediate interactions with Pop1 and Rpp40, respectively [].The structure of Rnp2 (ribonuclease P protein component 2) has a ferrodoxin-like fold composed of an α-β sandwich with antiparallel β-sheet and contains an extra C-terminal helix. |
