This family contains a ribonuclease P subunit of humans and yeast. Other members of the family include the probable archaeal homologues. This family includes SNM1 [2]. It is a subunit of RNase MRP (mitochondrial RNA processing), a ribonucleoprotein endoribonuclease that has roles in both mitochondrial DNA replication and nuclear 5.8S rRNA processing. SNM1 is an RNA binding protein that binds the MRP RNA specifically [2]. This subunit possibly binds the precursor tRNA [1].

1: Function and subnuclear distribution of Rpp21, a protein subunit of the human ribonucleoprotein ribonuclease P. Jarrous N, Reiner R, Wesolowski D, Mann H, Guerrier-Takada C, Altman S; RNA 2001;7:1153-1164. PMID:11497433

2: Mutagenesis of SNM1, which encodes a protein component of the yeast RNase MRP, reveals a role for this ribonucleoprotein endoribonuclease in plasmid segregation. Cai T, Reilly TR, Cerio M, Schmitt ME; Mol Cell Biol 1999;19:7857-7869. PMID:10523674