PROSITE documentation PDOC51942
Betacoronavirus Nsp3c-C domain profile


Coronaviruses (CoVs) are enveloped positive-strand RNA viruses that infect many species, including humans, other mammals, and birds. After infection, the host may develop respiratory, bowel, liver, and neurological diseases. Coronaviruses are divided into four genera: αcoronavirus, βcoronavirus, γcoronavirus, and Deltacoronavirus. SARS, SARS-CoV-2, BatCoV RaTG13 and Bat-SARS-like coronavirus (BATSL-CoVZXC21 and BAT-SL-CoVZC45) belong to the Sarbecovirus subgenus of βcoronavirus [E1].

The CoV replicase gene encodes two overlapping polyproteins, termed pp1a and pp1ab, which mediate viral replication and transcription. The polypeptides pp1a and pp1ab are processed by the action of a main protease (Nsp5) (see <PDOC51442>) and of one or two papain-like proteases (PLpro) (see <PDOC51124>) found in Nsp3 into non-structural proteins (Nsps) to form the replication/ transcription complex (RTC). Among these, Nsp3 is a glycosylated, multidomain, integral membrane protein. Nsp3 plays many roles in the viral life cycle. It can act as a scaffold protein to interact with itself and to bind other viral Nsps or host proteins. In particular, Nsp3 is essential for RTC formation. Nsp3 comprises various domains of functional and structural importance for virus replication, the organization of which differs between CoV genera, due to duplication or absence of some domains [1]. The Nsp3c-C (or SUD-C), which is conserved across multiple β-CoVs, is a Domain Preceding Ubl2 and PLpro (DPUP). The Nsp3c-C domain adopts a frataxin fold or double-wing motif, which is an α+β fold that is associated with protein/protein interactions, DNA binding, and metal ion binding. The Nsp3c-C domain binds to single-stranded RNA and recognizes purine bases more strongly than pyrimidine bases [2,3,4].

The Nsp3c-C domain consists of an antiparallel β-sheet with two α-helices at the N- and C-termini that pack on one side of the sheet (see <PDB:2KQW>) [1,2,3,,4].

The profile we developed covers the entire Nsp3c-C domain.

Last update:

October 2020 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

BCOV_NSP3C_C, PS51942; Betacoronavirus Nsp3c-C domain profile  (MATRIX)


1AuthorsLei J. Kusov Y. Hilgenfeld R.
TitleNsp3 of coronaviruses: Structures and functions of a large multi-domain protein.
SourceAntiviral. Res. 149:58-74(2018).
PubMed ID29128390

2AuthorsJohnson M.A. Chatterjee A. Neuman B.W. Wuethrich K.
TitleSARS coronavirus unique domain: three-domain molecular architecture in solution and RNA binding.
SourceJ. Mol. Biol. 400:724-742(2010).
PubMed ID20493876

3AuthorsChen Y. Savinov S.N. Mielech A.M. Cao T. Baker S.C. Mesecar A.D.
TitleX-ray Structural and Functional Studies of the Three Tandemly Linked Domains of Non-structural Protein 3 (nsp3) from Murine Hepatitis Virus Reveal Conserved Functions.
SourceJ. Biol. Chem. 290:25293-25306(2015).
PubMed ID26296883

4AuthorsHammond R.G. Tan X. Johnson M.A.
TitleSARS-unique fold in the Rousettus bat coronavirus HKU9.
SourceProtein. Sci. 26:1726-1737(2017).
PubMed ID28580734


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