Protein Domain : Nonstructural protein 13, 1B domain, coronavirus IPR044343

Type	Domain
Description	Helicase nonstructural protein 13 (NSP13) is encoded by the replicase polyprotein 1a/ab of coronaviruses and released after a proteolytic process. It plays a vital role in catalysing the unwinding of duplex oligonucleotides into single strands in an NTP-dependent manner. It is a multidomain protein which includes an N-terminal Cys/His rich zinc-binding domain (ZBD), followed by a stalk and 1B domains, and a helicase core that belongs to the superfamily SF1 of helicases, containing two RecA1 and RecA2 domains [ , ]. The stalk region connects the ZBD domain and 1B domain. Nsp13 adopts a triangular pyramid shape in which the two RecA1 and A2 and 1B domain form the triangular base, while N-terminal ZBD and stalk domains are arranged at the apex of the pyramid [, , ]. Recently, it has been reported that SARS-CoV-2 NSP13 as an interferon antagonist. It is involved in type I interferon (IFN-I) response as it binds and blocks TBK1 phosphorylation to inhibit interferon regulatory factor 3 (IRF3) which results in decreased IRF3 activation [ , ].This entry represents the 1B domain, which has a regulatory role modulating the nucleic acid substrate binding. Based on the structures from the related Equine arteritis virus (EAV) NSP10, it is likely that 1B domain forms a channel together with 1A and 2A domains that accommodates the single stranded nucleic acids [ , ].
Short Name	NSP13_1B_dom_CoV