This family contains a ribonuclease P subunit of humans and yeast. Other members of the family include the probable archaeal homologs. This family includes SNM1. 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. This subunit possibly binds the precursor tRNA.