Activating Compound | Comment | Organism | Structure |
---|---|---|---|
dsRNA | the enzyme is dependent on dsRNA, activation of isozyme OAs3 by 0.001 mg/ml, and of isozymes AS1 and OAS2 by 0.1 mg/ml, at optimals pH values | Homo sapiens |
Cloned (Comment) | Organism |
---|---|
three distinct forms of 2'-5'OAS exist in human cells, small, medium, and large, which contain one, two, and three OAS units, respectively, and are encoded by distinct genes, clustering of the genes encoding OAS1, OAS2, OAS3 and OASL on human chromosome 12q24.2, genetic organization, expression of isozyme OAS3 and the two forms of OAS2 in HeLa cells, expression of recombinant OAS2 in insect cells | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
additional information | substitutions of amino acids in front of the P-loop of Lys42 and Lys60 as well as that of Arg195 reduce the 2'-5'OAS activity at least 50fold. Furthermore substitutions in the Lys199 and Lys204 reduce the activity more than a 1000fold | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
additional information | three distinct forms of 2'-5'OAS exist in human cells, that show distinct subcellular localizations | Homo sapiens | - |
- |
nucleus | association of this form of OAS with membranes of the nuclear envelope and the rough endoplasmic reticulum | Homo sapiens | 5634 | - |
ribosome | OAS3 is mainly associated with the ribosomal fraction | Homo sapiens | 5840 | - |
rough endoplasmic reticulum | association of this form of OAS with membranes of the nuclear envelope and the rough endoplasmic reticulum | Homo sapiens | 5791 | - |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
160000 | - |
dimeric isozyme OAS2, gel filtration | Homo sapiens |
180000 | - |
tetrameric isozyme OAS1, gel filtration | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | - |
isozyme OAS1, two forms of isozyme OAS2, and isozyme OAS3 | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | isozyme OAS1 is specific for ATP, but isozyme OAS2 shows broad substrate specificity accepting diverse nucleotide triphosphates as donor substrates that give several products, overview. Isozymes OAS1 and OAS2 produce 2-5A oligomers, while isozyme OAS3 produces 2-5A dimers. GTP is an alternative substrate for the 2'-5'OAS, as donor as well as acceptor molecule. Nevertheless, competition experiments of GTP versus ATP points out that GTP exhibits a much higher affinity for the donor site of OAS than for the acceptor one. A monomeric OAS-like protein, OASL, is catalytically inactive | Homo sapiens | ? | - |
? | |
n ATP | reaction of OAS1 | Homo sapiens | pppA(2'p5'A)n + 2 diphosphate | - |
? | |
NTP + pppA2'p5'A | reaction of OAS2, broad spectrum of accepted donor substrates, including ATP, GTP, CTP, UTP, ITP, and their deoxy variants, overview | Homo sapiens | pppA2'p5'Ap2'p5'N + 2 diphosphate | - |
? | |
NTP + RpA | reaction of OAS3, broad spectrum of accepted donor substrates, including ATP, GTP, CT, UTP, ITP, and their deoxy variants, and of acceptor substrates including tRNA, A5'ppp5''A, A5'pppp5''A, NAD+, and polyA, overview | Homo sapiens | RpA2'p5'N + 2 diphosphate | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | 2 * 56000-59000, isozyme OAS2, two dimers form a tetramer, SDS-PAGE | Homo sapiens |
homotetramer | 4 * 56000-59000, isozyme OAS1, SDS-PAGE | Homo sapiens |
More | three distinct forms of 2'-5'OAS exist in human cells, small, medium, and large, which contain one, two, and three OAS units, respectively, and are encoded by distinct genes clustered on the 2'-5OAS locus on human chromosome 12. The monomeric OAS-like protein, OASL, is catalytically inactive | Homo sapiens |
trimer | 3 * 56000-59000, isozyme OAS3, SDS-PAGE | Homo sapiens |
Synonyms | Comment | Organism |
---|---|---|
2'-5' oligoadenylate synthetase | - |
Homo sapiens |
2'-5'OAS | - |
Homo sapiens |
OAS1 | - |
Homo sapiens |
OAS2 | - |
Homo sapiens |
OAS3 | - |
Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.6 | - |
isozyme OAS2 | Homo sapiens |
7.5 | - |
isozyme OAS3 | Homo sapiens |
Organism | Comment | Expression |
---|---|---|
Homo sapiens | induction by interferon | up |
General Information | Comment | Organism |
---|---|---|
additional information | the active site is composed of three aspartic acids, Asp76, Asp78, and Asp148, and two domains found right after the dsRNA binding regions constituting a catalytic groove on the opposite face of the protein, which has the form of an erythrocyte, where the two ends are close | Homo sapiens |
physiological function | 2'-5'OASs are initially described as important components of the antiviral action of interferon. But the structural and functional complexity of the human 2'-5'OAS family implying that these proteins may have distinct roles in the cell. 2'-5'OAS forms 2-5A molecules that activate the latent endoribonuclease. The RNAse L. OAS1 and OAS2 mediate resistance to virus infections, OAS3 appears to confer sensitivity to dsRNA-induced apoptosis via a mechanism that does not require the synthesis of 2-5A | Homo sapiens |