Table 1.

Conservation of RNase P protein components across the domains of life. RnpA proteins from various Bacteria share homology to each other, but not to archaeal or eukaryotic proteins. Archaeal and eukaryotic nuclear RNase P proteins share sequence homology with proteins on the same row. Protein-only RNase P components do not share homology with any of the RNA-based RNase P protein components.

Bacteria	Archaea 1	Eukarya
		RNA-based		PRORP
		Yeast	Human	Human	Plant
RnpA
	Mth687p	POP5	hPOP5
	Mth11p	POP4	RPP29
	Mth688p	RPP1	RPP30
	Mth1618p	RPR2	RPP21
	L7Ae 2	POP3	RPP38
		POP1	hPOP1
		POP6	RPP25
		POP7	RPP20
		POP8
			RPP14
			RPP40
				MRPP1
				MRPP2
				MRPP3	PRORP1–3

¹ Naming for RNase P proteins from Methanobacter thermoautotrophicus [59]. ² L7Ae homologs are only associated with M-type archaeal RNase P [47].