| 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]
Publication Abstract from PubMed
Phylogenetic analysis has demonstrated that some positive sense RNA viruses can be classified into the picornavirus-like supercluster, which includes picornaviruses, caliciviruses and coronaviruses. These viruses possess 3C or 3C-like proteases (3Cpro or 3CLpro, respectively) which contain a typical chymotrypsin-like fold and a catalytic triad (or dyad) with a Cys residue as a nucleophile. The conserved key sites of 3Cpro or 3CLpro may serve as an attractive target for the design of broad-spectrum antivirals for multiple viruses in the supercluster. We have previously reported the structure-based design and synthesis of potent protease inhibitors of Norwalk virus (NV), a member of the Caliciviridae family. We report herein the broad-spectrum antiviral activities of three compounds possessing a common dipeptidyl residue with different warheads, aldehyde (GC373), bisulfite adduct (GC376) and alpha-ketoamide (GC375), against viruses that belong to the supercluster. All compounds were highly effective against the majority of tested viruses with the half maximal inhibitory concentration in the high nanomolar or low micromolar range in the enzyme and/or cell-based assays with high therapeutic indices. We also report the high-resolution X-ray cocrystal structures of the NV 3CLpro-, poliovirus 3Cpro- or transmissible gastroenteritis virus 3CLpro-inhibitor GC376 complex that show the compound covalently bound to a nucleophilic Cys residue in the catalytic site of the corresponding protease. We conclude that these compounds have the potential to be developed as antiviral therapeutics aimed at a single virus or multiple viruses in the picornavirus-like supercluster by targeting 3Cpro or 3CLpro.
Broad-Spectrum Antivirals against 3C or 3C-like Proteases of Picornaviruses, Noroviruses and Coronaviruses.,Kim Y, Lovell S, Tiew KC, Mandadapu SR, Alliston KR, Battaile KP, Groutas WC, Chang KO J Virol. 2012 Aug 22. PMID:22915796[25]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ Kim Y, Lovell S, Tiew KC, Mandadapu SR, Alliston KR, Battaile KP, Groutas WC, Chang KO. Broad-Spectrum Antivirals against 3C or 3C-like Proteases of Picornaviruses, Noroviruses and Coronaviruses. J Virol. 2012 Aug 22. PMID:22915796 doi:http://dx.doi.org/10.1128/JVI.01348-12
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