Alphacoronavirus (taxid:693996)
VIRION
Enveloped, spherical, about 120 nm in diameter. The RNA genome is associated with the N protein to form the nucleocapsid. see Neuman BW et al. for virion cryo-electron microscopy analysis.
GENOME
Monopartite, linear ssRNA(+) genome of 27-32kb in size (the largest of all RNA virus genomes). Capped, and polyadenylated. The leader RNA (65-89 bp) at the 5' end of the genome is also present at the end of each subgenomic RNAs.
GENE EXPRESSION
The virion RNA is infectious and serves as both the genome and viral messenger RNA. Genomic RNA encodes for ORF1a, as for ORF1b, it is translated by ribosomal frameshifting. Resulting polyproteins pp1a and pp1ab are processed into the viral polymerase (RdRp) and other non-structural proteins involved in RNA synthesis. Structural proteins are expressed as subgenomic RNAs. Each RNA (genomic and subgenomic) is translated to yield only the protein encoded by the 5'-most ORF.
ENZYMES
- RNA-dependent RNA polymerase [P0C6X1]
- Proofreading exoribonuclease (ExoN) [P0C6X1]
- Nido-type capping (GDP polyribonucleotidyltransferase, N7methyltransferase, 2'O methylase) [P0C6X1]
- EndoU ribonuclease [P0C6X1]
- Papain-like protease (Peptidase C16) [P0C6X1]
- 3C-like proteinase (Peptidase C30) [P0C6X1]
- Helicase [P0C6X1]
- ADP-Ribosylhydrolase [P0C6X1]
REPLICATION
CYTOPLASMIC
- Attachement of the viral S protein (maybe also HE if present) to host receptors mediates endocytosis of the virus into the host cell.
- Fusion of virus membrane with the endosomal membrane (probably mediated by S2), ssRNA(+) genome is released into the cytoplasm.
- Synthesis and proteolytic cleavage of the replicase polyprotein.
- Replication occurs in viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
- The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
- Synthesis of structural proteins encoded by subgenomic mRNAs.
- Assembly and budding at ERGIC compartment.
- Release of new virions by exocytosis.
Host-virus interaction
Innate immune response inhibition
TGEV protein 7 may counteract host antiviral response, possibly by modulating PP1 activity 
.
Matching UniProtKB/Swiss-Prot entries
(all links/actions below point to uniprot.org website)92 entries grouped by protein
12 entries
Nucleoprotein (Nucleocapsid protein) (NC) (Protein N)
3 entries
Non-structural protein 3 (ns3) (Accessory protein 3a)
5 entries
Non-structural protein 3a (ns3a) (Accessory protein 3a)
6 entries
Putative truncated non-structural protein 3b (ns3b) (Accessory protein 3b)
2 entries
Non-structural protein 3x (ns3x) (Accessory protein 3x) (ns3b)
1 entry
Non-structural protein 4a (ns4a) (Accessory protein 4a)
1 entry
Non-structural protein 4b (ns4b) (Accessory protein 4b)
9 entries
Non-structural protein 7a (ns7a) (11 kDa protein) (Accessory protein 7a) (X3 protein)
5 entries
Non-structural protein 7b (ns7b) (Accessory protein 7b)
5 entries
Replicase polyprotein 1a (pp1a) (ORF1a polyprotein)
6 entries
Replicase polyprotein 1ab (pp1ab) (ORF1ab polyprotein)
14 entries
Spike glycoprotein (S glycoprotein) (E2) (Peplomer protein)
11 entries
Envelope small membrane protein (E protein) (sM protein)
12 entries
Membrane protein (M protein) (E1 glycoprotein) (Matrix glycoprotein) (Membrane glycoprotein)
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Lucheng Rn rat coronavirus taxid:1508224
| Protein | ModelArchive |
| Envelope protein | ma-jd-viral-63802 |
| Membrane protein (M protein) (E1 glycoprotein) (Matrix glycoprotein) (Membrane... | ma-jd-viral-03155 |
| Nucleoprotein | ma-jd-viral-63037 |