RNase PH is a tRNA nucleotidyltransferase, present in archaea and bacteria, that is involved in tRNA processing. Contrary to hydrolytic enzymes, it is a phosphorolytic enzyme, meaning that it uses inorganic phosphate as a reactant to cleave nucleotide-nucleotide bonds, releasing diphosphate nucleotides. The active structure of the proteins is a homohexameric complex, consisting of three ribonuclease (RNase) PH dimers.^[1] RNase PH has homologues in many other organisms, which are referred to as RNase PH-like proteins. The part of another larger protein with a domain that is very similar to RNase PH is called an RNase PH domain (RPD).

Ribonuclease PH
Structure of the RNase PH hexamer
Identifiers
Symbol	RNASEPH
Other data
EC number	2.7.7.56