RNase PH

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
Crystal structure 1UDN.jpg
Structure of the RNase PH hexamer
Other data
EC number2.7.7.56

See alsoEdit

Two highly related exoribonuclease complexes:


  1. ^ Ishii R, Nureki O, Yokoyama S (August 2003). "Crystal structure of the tRNA processing enzyme RNase PH from Aquifex aeolicus". The Journal of Biological Chemistry. 278 (34): 32397–404. doi:10.1074/jbc.M300639200. PMID 12746447.

External linksEdit