RNASEH2A
Encyclopedia
RRibonuclease H2 subunit A, also known as RNase H2 subunit A, is an enzyme
that in humans is encoded by the RNASEH2A gene
.
enzyme (RNAseH2). RNAseH2 is the major source of ribonuclease H activity in mammalian cells and endonucleolytically cleaves ribonucleotide
s. It is predicted to remove Okazaki fragment
RNA primers during lagging strand DNA
synthesis and to excise single ribonucleotides from DNA-DNA duplexes.
(AGS), an autosomal recessive neurological disorder characterized by progressive microcephaly
and psychomotor retardation, intracranial calcifications, elevated levels of interferon-alpha
and white blood cells in the cerebrospinal fluid
.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that in humans is encoded by the RNASEH2A gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Function
The protein encoded by this gene is a component of the heterotrimeric type II ribonuclease HRNase H
The enzyme RNase H is a non-specific endonuclease and catalyzes the cleavage of RNA via a hydrolytic mechanism. Members of the RNase H family can be found in nearly all organisms, from archaea to bacteria and eukaryota....
enzyme (RNAseH2). RNAseH2 is the major source of ribonuclease H activity in mammalian cells and endonucleolytically cleaves ribonucleotide
Ribonucleotide
A ribonucleotide or ribotide is a nucleotide in which a purine or pyrimidine base is linked to a ribose molecule and exactly one phosphate group. In living organisms the most common bases for ribonucleotides are adenine , guanine , cytosine , or uracil ....
s. It is predicted to remove Okazaki fragment
Okazaki fragment
Okazaki fragments are short molecules of single-stranded DNA that are formed on the lagging strand during DNA replication. They are between 1,000 to 2,000 nucleotides long in Escherichia coli and are between 100 to 200 nucleotides long in eukaryotes....
RNA primers during lagging strand DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
synthesis and to excise single ribonucleotides from DNA-DNA duplexes.
Clinical significance
Mutations in this gene cause Aicardi-Goutieres syndromeAicardi-Goutieres syndrome
Aicardi–Goutières syndrome is a rare genetic disorder. It is also known as Cree encephalitis and pseudo-TORCH syndrome, both of which were once considered separate disorders. It is a type of leukodystrophy and is usually fatal within the first few years...
(AGS), an autosomal recessive neurological disorder characterized by progressive microcephaly
Microcephaly
Microcephaly is a neurodevelopmental disorder in which the circumference of the head is more than two standard deviations smaller than average for the person's age and sex. Microcephaly may be congenital or it may develop in the first few years of life...
and psychomotor retardation, intracranial calcifications, elevated levels of interferon-alpha
Interferon
Interferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...
and white blood cells in the cerebrospinal fluid
Cerebrospinal fluid
Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...
.