1px5
Crystal structure of the 2'-specific and double-stranded RNA-activated interferon-induced antiviral protein 2'-5'-oligoadenylate synthetase
Structural highlights
FunctionOAS1_PIG Interferon-induced, dsRNA-activated antiviral enzyme which plays a critical role in cellular innate antiviral response. In addition, it may also play a role in other cellular processes such as apoptosis, cell growth, differentiation and gene regulation. Synthesizes higher oligomers of 2'-5'-oligoadenylates (2-5A) from ATP which then bind to the inactive monomeric form of ribonuclease L (RNase L) leading to its dimerization and subsequent activation. Activation of RNase L leads to degradation of cellular as well as viral RNA, resulting in the inhibition of protein synthesis, thus terminating viral replication. Can mediate the antiviral effect via the classical RNase L-dependent pathway or an alternative antiviral pathway independent of RNase L. The secreted form displays antiviral effect against vesicular stomatitis virus (VSV), herpes simplex virus type 2 (HSV-2), and encephalomyocarditis virus (EMCV) and stimulates the alternative antiviral pathway independent of RNase L.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed2'-5'-oligoadenylate synthetases are interferon-induced, double-stranded RNA-activated antiviral enzymes which are the only proteins known to catalyze 2'-specific nucleotidyl transfer. This crystal structure of a 2'-5'-oligoadenylate synthetase reveals a structural conservation with the 3'-specific poly(A) polymerase that, coupled with structure-guided mutagenesis, supports a conserved catalytic mechanism for the 2'- and 3'-specific nucleotidyl transferases. Comparison with structures of other superfamily members indicates that the donor substrates are bound by conserved active site features while the acceptor substrates are oriented by nonconserved regions. The 2'-5'-oligoadenylate synthetases are activated by viral double-stranded RNA in infected cells and initiate a cellular response by synthesizing 2'-5'-oligoadenylates, which in turn activate RNase L. This crystal structure suggests that activation involves a domain-domain shift and identifies a putative dsRNA activation site that is probed by mutagenesis, thus providing structural insight into cellular recognition of viral double-stranded RNA. Crystal structure of the 2'-specific and double-stranded RNA-activated interferon-induced antiviral protein 2'-5'-oligoadenylate synthetase.,Hartmann R, Justesen J, Sarkar SN, Sen GC, Yee VC Mol Cell. 2003 Nov;12(5):1173-85. PMID:14636576[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
