RNASEH1

This gene encodes an endonuclease that specifically degrades the RNA of RNA-DNA hybrids and plays a key role in DNA replication and repair. Alternate in-frame start codon initiation results in the production of alternate isoforms that are directed to the mitochondria or to the nucleus. The production of the mitochondrial isoform is modulated by an upstream open reading frame (uORF). Mutations in this gene have been found in individuals with progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 2. Alternative splicing results in additional coding and non-coding transcript variants. Pseudogenes of this gene have been defined on chromosomes 2 and 17. [provided by RefSeq, Jul 2017]

ribonuclease H1

Endonuclease that specifically degrades the RNA of RNA-DNA hybrids (PubMed:10497183).
Plays a role in RNA polymerase II (RNAp II) transcription termination by degrading R-loop RNA-DNA hybrid formation at G-rich pause sites located downstream of the poly(A) site and behind the elongating RNAp II (PubMed:21700224).

Biological Process DNA replication, removal of RNA primerManual Assertion Based On ExperimentIBA:GO_Central
Biological Process RNA catabolic processManual Assertion Based On ExperimentTAS:ProtInc
Biological Process RNA phosphodiester bond hydrolysis, endonucleolyticManual Assertion Based On ExperimentIBA:GO_Central

Cytoplasm

Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 2 (PEOB2):
A form of progressive external ophthalmoplegia, a mitochondrial myopathy characterized by progressive paralysis of the levator palpebrae, orbicularis oculi, and extraocular muscles. PEOB2 patients manifest exercise intolerance, muscle weakness, and signs and symptoms of spinocerebellar ataxia, such as impaired gait and dysarthria. Some patients may have respiratory insufficiency.