2c8i

Structural highlights

Function

[POLG_EC11G] Capsid proteins VP1, VP2, VP3 and VP4 form a closed capsid enclosing the viral positive strand RNA genome. 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. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes (By similarity). Capsid proteins interact with host CD55 to provide virion attachment to target cell. VP0 precursor is a component of immature procapsids (By similarity). Protein 2A is a cysteine protease that is responsible for the cleavage between the P1 and P2 regions. It cleaves the host translation initiation factor EIF4G1, in order to shut down the capped cellular mRNA transcription (By similarity). Protein 2B affects membrane integrity and cause an increase in membrane permeability (By similarity). Protein 2C associates with and induces structural rearrangements of intracellular membranes. It displays RNA-binding, nucleotide binding and NTPase activities (By similarity). Protein 3A, via its hydrophobic domain, serves as membrane anchor. It also inhibits endoplasmic reticulum-to-Golgi transport (By similarity). Protein 3C is a cysteine protease that generates mature viral proteins from the precursor polyprotein. In addition to its proteolytic activity, it binds to viral RNA, and thus influences viral genome replication. RNA and substrate bind co-operatively to the protease (By similarity). RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals (By similarity). [DAF_HUMAN] This protein recognizes C4b and C3b fragments that condense with cell-surface hydroxyl or amino groups when nascent C4b and C3b are locally generated during C4 and c3 activation. Interaction of daf with cell-associated C4b and C3b polypeptides interferes with their ability to catalyze the conversion of C2 and factor B to enzymatically active C2a and Bb and thereby prevents the formation of C4b2a and C3bBb, the amplification convertases of the complement cascade.^[1]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

References

1. ↑ Ward T, Pipkin PA, Clarkson NA, Stone DM, Minor PD, Almond JW. Decay-accelerating factor CD55 is identified as the receptor for echovirus 7 using CELICS, a rapid immuno-focal cloning method. EMBO J. 1994 Nov 1;13(21):5070-4. PMID:7525274
2. ↑ Pettigrew DM, Williams DT, Kerrigan D, Evans DJ, Lea SM, Bhella D. Structural and functional insights into the interaction of echoviruses and decay-accelerating factor. J Biol Chem. 2006 Feb 24;281(8):5169-77. Epub 2005 Nov 4. PMID:16272562 doi:10.1074/jbc.M510362200