RNH

RNH is an acronym that can refer to several concepts, depending on the field. In biology and biochemistry, it most commonly denotes ribonuclease H, an enzyme that cleaves the RNA strand of RNA–DNA hybrids. In gene nomenclature, the enzyme is encoded by genes named rnh (for instance rnhA and rnhB in bacteria).

Ribonuclease H enzymes exist as Type 1 and Type 2. In eukaryotes they form through two families: RNase H1, a single polypeptide, and RNase H2, a heterotrimeric complex. They require divalent metal ions for catalysis. Functions include removal of RNA primers from Okazaki fragments and processing RNA–DNA hybrids that arise during transcription and reverse transcription. In humans, RNASEH2 is a three-subunit complex (A, B, C) and mutations in these subunits are linked to Aicardi–Goutières syndrome, a neuroinflammatory disorder. RNase H activity is used in molecular biology workflows to separate RNA from RNA–DNA hybrids in certain protocols.

In chemistry, RNH is used as a general representation in reaction schemes for an amine fragment, with R denoting an organic substituent and NH indicating nitrogen bound to hydrogen. This use is less standardized than RNase H nomenclature and depends on context.