Ribonuclease H1 (RNase H1)

Ribonuclease H1 (RNase H1) is a non-sequence-specific endonuclease enzyme found in prokaryotes and eukaryotes, encoded in humans by the RNASEH1 gene. It specifically cleaves the RNA strand of RNA/DNA hybrids through a hydrolytic mechanism, playing a crucial role in the removal of RNA from such hybrids, most notably in the context of R-loop structures that form during transcription and replication. RNase H1 maintains genome stability by preventing the accumulation of these hybrids, which can otherwise lead to genomic instability. Structurally, the enzyme contains a characteristic DEDD active site motif, requiring magnesium ions for catalysis. Its activity has been harnessed therapeutically, particularly in antisense oligonucleotide (ASO) therapies targeting disease-associated RNA. RNase H1 dysfunction is associated with impaired DNA repair, increased R-loop formation, and is implicated as a regulatory factor in some cancer types[1][2][3][5][8].

Other names

RNH1RNASEH1RNHRibonuclease H (when referring to type 1)ribonuclease HI (in prokaryotes)

Hydrolytic cleavage of RNA in RNA/DNA duplexes Removal of RNA from RNA-DNA hybrids formed during DNA replication, repair, and transcription