Component of ribonuclease P, a protein complex that generates mature tRNA molecules by cleaving their 5'-ends. Also a component of RNase MRP, which cleaves pre-rRNA sequences. Endonucleolytic cleavage of RNA, removing 5'-extranucleotides from tRNA precursor. Component of nuclear RNase P and RNase MRP complexes. RNase P consists of an RNA moiety and at least 9 protein subunits including POP1, POP3, POP4, POP5, POP6, POP7, POP8, RPP1 and RPR2. RNase MRP complex consists of an RNA moiety and at least 10 protein subunits including POP1, POP3, POP4, POP5, POP6, POP7, POP8, RMP1, RPP1 and SNM1, many of which are shared with the RNase P complex. Present with 6300 molecules/cell in log phase SD medium. Belongs to the eukaryotic/archaeal RNase P protein component 3 family.