Activating Compound | Comment | Organism | Structure |
---|---|---|---|
mitochondrial protein P32 | slightly enhances the RNase H1 enzymatic activity | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
A185V | naturally occuring mutation of RNase H1, that is involved in adult-onset mitochondrial encephalomyopathy. Both RNase H1:V142I and RNase H1:A185V, alone or in combination, display impaired R-loop processing activity compared to wild-type RNase H1. As a consequence, the mutant RNase H1 proteins cannot support origin-specific initiation of DNA replication in vitro | Homo sapiens |
V142I | naturally occuring mutation of RNase H1, that is involved in adult-onset mitochondrial encephalomyopathy. Both RNase H1:V142I and RNase H1:A185V, alone or in combination, display impaired R-loop processing activity compared to wild-type RNase H1. As a consequence, the mutant RNase H1 proteins cannot support origin-specific initiation of DNA replication in vitro | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
mtSSB | repressive effect of mtSSB, mildly at 20 nM, strongly at 120 nM | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrion | - |
Homo sapiens | 5739 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | Homo sapiens | RNase H1 is an RNase H enzyme capable of cleaving RNA-DNA hybrids. It can cleave hybrids that are down to approximately 6 nucleotides in length. The enzyme can also cleave Okazaki fragment-like structures, leaving approximately two ribonucleotides next to the RNA-DNA junction | ? | - |
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Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | O60930 | - |
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Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | RNase H1 is an RNase H enzyme capable of cleaving RNA-DNA hybrids. It can cleave hybrids that are down to approximately 6 nucleotides in length. The enzyme can also cleave Okazaki fragment-like structures, leaving approximately two ribonucleotides next to the RNA-DNA junction | Homo sapiens | ? | - |
? | |
additional information | RNase H1 can process mitochondrial R-loops. RNase H1 gradually degrades R-loops in a concentration-dependent manner, generating shorter RNA species. The shorter RNA species may be involved in hybrid G-quadruplex formation, and therefore partially resistant to RNase H1 degradation. With a template lacking L-strand promoter (LSP), RNase H1 has no apparent effects on DNA synthesis and no short DNA products are observed when RNase H1 is added together with mtSSB. Priming is dependent on R-loops, the presence of LSP. No DNA synthesis from processed LSP R-loops in the absence of RNase H1. Upon addition of RNase H1, replication products with sizes between 12 and 21 nts are observed. The highest levels of DNA synthesis are observed at 2 nM of RNase H1 | Homo sapiens | ? | - |
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Synonyms | Comment | Organism |
---|---|---|
RNase H1 | - |
Homo sapiens |
General Information | Comment | Organism |
---|---|---|
malfunction | disease-causing mutations impairs the process of RNase H1 direction of origin-specific initiation of DNA replication in human mitochondria. Depletion of RNase H1 causes a reduction in mtDNA level. In an RNase H1-deficient patient cell line, the precise initiation of mtDNA replication is lost and DNA synthesis is initiated from multiple sites throughout the mitochondrial control region. Impaired RNase H1 activity changes replication initiation in vivo. Effects of disease causing mutations in RNASEH1, which are associated with adult-onset mitochondrial encephalomyopathy, phenotype and mechanism, overview | Homo sapiens |
metabolism | RNase H1 involvement in mtDNA synthesis, detailed overview. RNase H1 is involved in primer processing in human mitochondria | Homo sapiens |
physiological function | RNase H1 is required for mtDNA replication, it directs origin-specific initiation of DNA replication in human mitochondria. RNase H1 is required for R-loop processing, primer formation, and mtDNA maintenance in vivo. Both R-loop formation and DNA replication initiation are stimulated by the mitochondrial single-stranded DNA binding protein. In addition to the potential role in R-loop processing, RNase H1 has also been proposed to be involved in mitochondrial pre-rRNA processing by interacting with the mitochondrial protein P32, which slightly enhances the RNase H1 enzymatic activity | Homo sapiens |