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 []. In bacteria, the catalytic RNA (typically ~120kDa) is aided by a small protein cofactor (~14kDa) []. 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 [].This entry represents Rpp40 from eukaryotes. 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 [].
