Ribonuclease H2 subunit A, also known as RNase H2 subunit A, is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that in humans is encoded by the ''RNASEH2A''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
The protein encoded by this gene is a component of the heterotrimeric type II
ribonuclease H enzyme (RNaseH2). The other two subunits are the non-catalytic
RNASEH2B and
RNASEH2C. RNaseH2 is the major source of ribonuclease H activity in mammalian cells and endonucleolytically cleaves
ribonucleotides. It is predicted to remove
Okazaki fragment RNA primers during lagging strand
DNA
Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...
synthesis and to excise single ribonucleotides from DNA-DNA duplexes.
Clinical significance
Mutations in this gene cause
Aicardi–Goutières syndrome (AGS), an
autosomal recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...
neurological disorder characterized by progressive
microcephaly and psychomotor retardation, intracranial calcifications, elevated levels of
interferon-alpha and white blood cells in the
cerebrospinal fluid.
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Aicardi-Goutières Syndrome OMIM entries on Aicardi-Goutieres syndrome*
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