8x3v

Structural highlights

Function

POLG_EMCV Forms a complex with host RAN and probably binds to exportins carrying activated MAPK in order to mediate the hyperphosphorylation of host Phe/Gly containing nuclear pore proteins (Nups) resulting in cessation of active nucleocytoplasmic transport (By similarity). Proteins with NLS signals fail to import, cellular mRNAs fail to export, and some proteins small enough for diffusion are not retained anymore (efflux) (By similarity). The resulting inhibition of cellular protein synthesis serves to ensure maximal viral gene expression and to evade host immune response (By similarity).[UniProtKB:Q66765] Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. Together they form an icosahedral capsid composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms.VP4 lies on the inner surface of the protein shell formed by VP1, VP2 and VP3. All the three latter proteins contain a beta-sheet structure called beta-barrel jelly roll. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes.[UniProtKB:P12296] Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. Together they form an icosahedral capsid composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms.VP4 lies on the inner surface of the protein shell formed by VP1, VP2 and VP3. All the three latter proteins contain a beta-sheet structure called beta-barrel jelly roll. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes.[UniProtKB:P12296] Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. Together they form an icosahedral capsid composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms.VP4 lies on the inner surface of the protein shell formed by VP1, VP2 and VP3. All the three latter proteins contain a beta-sheet structure called beta-barrel jelly roll. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes.[UniProtKB:P12296] Lies on the inner surface of the capsid shell (By similarity). After binding to the host receptor, the capsid undergoes conformational changes (By similarity). Capsid protein VP4 is released, capsid protein VP1 N-terminus is externalized, and together, they shape a pore in the host membrane through which the viral genome is translocated into the host cell cytoplasm (By similarity). After genome has been released, the channel shrinks (By similarity).[UniProtKB:P03300][UniProtKB:P12296] VP0 precursor is a component of immature procapsids.[UniProtKB:P08617] Involved in host translation shutoff by inhibiting cap-dependent mRNA translation (By similarity). Nuclear localization is required for this function (By similarity). The resulting inhibition of cellular protein synthesis serves to ensure maximal viral gene expression and to evade host immune response (By similarity). Inhibits the phosphorylation of the leader protein (By similarity). Binds to the RNA stem-loop essential for the ribosomal frameshift event and trans-activates the production of protein 2B* (By similarity).[UniProtKB:P12296][UniProtKB:Q66765] Affects membrane integrity and causes an increase in membrane permeability. Associates with and induces structural rearrangements of intracellular membranes (By similarity). It displays RNA-binding, nucleotide binding and NTPase activities (By similarity). Interacts with IFIH1/MDA5 to inhibit the induction of the IFN-beta signal pathway (PubMed:30312637).[UniProtKB:P03305][UniProtKB:P08545]^[1] Serves as membrane anchor via its hydrophobic domain. Forms a primer, VPg-pU, which is utilized by the polymerase for the initiation of RNA chains.^[2] Cysteine protease that generates mature viral proteins from the precursor polyprotein (By similarity). In addition to its proteolytic activity, it binds to viral RNA, and thus influences viral genome replication. RNA and substrate cooperatively bind to the protease. Cleaves host PABP1, this cleavage is important for viral replication (PubMed:22837200). Cleaves host TANK and disrupts the TANK-TBK1-IKKepsilon-IRF3 complex, thereby inhibiting the induction of the IFN-beta signal pathway (PubMed:26363073, PubMed:28487378).[UniProtKB:P12296]^{[3] [4] [5]} Replicates the genomic and antigenomic RNAs by recognizing replications specific signals (By similarity). Performs VPg uridylylation (By similarity).[UniProtKB:P12296]

References

1. ↑ Li L, Fan H, Song Z, Liu X, Bai J, Jiang P. Encephalomyocarditis virus 2C protein antagonizes interferon-β signaling pathway through interaction with MDA5. Antiviral Res. 2019 Jan;161:70-84. PMID:30312637 doi:10.1016/j.antiviral.2018.10.010
2. ↑ Vartapetian AB, Koonin EV, Agol VI, Bogdanov AA. Encephalomyocarditis virus RNA synthesis in vitro is protein-primed. EMBO J. 1984 Nov;3(11):2593-8. PMID:6096134 doi:10.1002/j.1460-2075.1984.tb02179.x
3. ↑ Kobayashi M, Arias C, Garabedian A, Palmenberg AC, Mohr I. Site-specific cleavage of the host poly(A) binding protein by the encephalomyocarditis virus 3C proteinase stimulates viral replication. J Virol. 2012 Oct;86(19):10686-94. PMID:22837200 doi:10.1128/JVI.00896-12
4. ↑ Huang L, Liu Q, Zhang L, Zhang Q, Hu L, Li C, Wang S, Li J, Zhang Y, Yu H, Wang Y, Zhong Z, Xiong T, Xia X, Wang X, Yu L, Deng G, Cai X, Cui S, Weng C. Encephalomyocarditis Virus 3C Protease Relieves TRAF Family Member-associated NF-κB Activator (TANK) Inhibitory Effect on TRAF6-mediated NF-κB Signaling through Cleavage of TANK. J Biol Chem. 2015 Nov 13;290(46):27618-32. PMID:26363073 doi:10.1074/jbc.M115.660761
5. ↑ Huang L, Xiong T, Yu H, Zhang Q, Zhang K, Li C, Hu L, Zhang Y, Zhang L, Liu Q, Wang S, He X, Bu Z, Cai X, Cui S, Li J, Weng C. Encephalomyocarditis virus 3C protease attenuates type I interferon production through disrupting the TANK-TBK1-IKKε-IRF3 complex. Biochem J. 2017 Jun 9;474(12):2051-2065. PMID:28487378 doi:10.1042/BCJ20161037