6psz

Structural highlights

Function

POLG_POL1M 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. The interaction of five VP1 proteins in the fivefold axes results in a prominent protusion extending to about 25 Angstroms from the capsid shell. The resulting structure appears as a steep plateau encircled by a valley or cleft. This depression also termed canyon is the receptor binding site. The capsid interacts with human PVR at this site to provide virion attachment to target cell. This attachment induces virion internalization predominantly through clathrin- and caveolin-independent endocytosis in Hela cells and through caveolin-mediated endocytosis in brain microvascular endothelial cells. VP4 and VP1 subsequently undergo conformational changes leading to the formation of a pore in the endosomal membrane, thereby delivering the viral genome into the cytoplasm.^{[1] [2] [3]} VP0 precursor is a component of immature procapsids (By similarity).^{[4] [5] [6]} 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.^{[7] [8] [9]} Protein 2B affects membrane integrity and cause an increase in membrane permeability (By similarity).^{[10] [11] [12]} Protein 2C associates with and induces structural rearrangements of intracellular membranes. It displays RNA-binding, nucleotide binding and NTPase activities.^{[13] [14] [15]} Protein 3A, via its hydrophobic domain, serves as membrane anchor. It also inhibits endoplasmic reticulum-to-Golgi transport (By similarity).^{[16] [17] [18]} 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).^{[19] [20] [21]} RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals (By similarity).^{[22] [23] [24]}

References

1. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
2. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
3. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
4. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
5. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
6. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
7. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
8. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
9. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
10. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
11. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
12. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
13. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
14. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
15. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
16. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
17. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
18. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
19. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
20. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
21. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004
22. ↑ Ventoso I, MacMillan SE, Hershey JW, Carrasco L. Poliovirus 2A proteinase cleaves directly the eIF-4G subunit of eIF-4F complex. FEBS Lett. 1998 Sep 11;435(1):79-83. PMID:9755863
23. ↑ Bubeck D, Filman DJ, Cheng N, Steven AC, Hogle JM, Belnap DM. The structure of the poliovirus 135S cell entry intermediate at 10-angstrom resolution reveals the location of an externalized polypeptide that binds to membranes. J Virol. 2005 Jun;79(12):7745-55. PMID:15919927 doi:79/12/7745
24. ↑ Bergelson JM. New (fluorescent) light on poliovirus entry. Trends Microbiol. 2008 Feb;16(2):44-7. doi: 10.1016/j.tim.2007.12.004. Epub 2008 , Jan 10. PMID:18191571 doi:10.1016/j.tim.2007.12.004