Component of ribonuclease P, a ribonucleoprotein complex that generates mature tRNA molecules by cleaving their 5'-ends (By similarity). Also a component of the MRP ribonuclease complex, which cleaves pre-rRNA sequences (By similarity). Endonucleolytic cleavage of RNA, removing 5'-extranucleotides from tRNA precursor. Component of nuclear RNase P and RNase MRP ribonucleoproteins (By similarity). Several subunits of RNase P are also part of the RNase MRP complex (By similarity).