1fpn
From Proteopedia
HUMAN RHINOVIRUS SEROTYPE 2 (HRV2)
Structural highlights
Function[POLG_HRV2] 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 capsid interacts with human VLDLR to provide virion attachment to target cell. This attachment induces virion internalization predominantly through clathrin-mediated endocytosis. 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] VP0 precursor is a component of immature procapsids (By similarity).[3] [4] 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.[5] [6] Protein 2B affects membrane integrity and cause an increase in membrane permeability (By similarity).[7] [8] Protein 2C associates with and induces structural rearrangements of intracellular membranes. It displays RNA-binding, nucleotide binding and NTPase activities (By similarity).[9] [10] Protein 3A, via its hydrophobic domain, serves as membrane anchor (By similarity).[11] [12] 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).[13] [14] RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals (By similarity).[15] [16] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHuman rhinoviruses are classified into a major and a minor group based on their binding to ICAM-1 or to members of the LDL-receptor family, respectively. They can also be divided into groups A and B, according to their sensitivity towards a panel of antiviral compounds. The structure of human rhinovirus 2 (HRV2), which uses the LDL receptor for cell attachment and is included in antiviral group B, has been solved and refined at 2.6 A resolution by X-ray crystallography to gain information on the peculiarities of rhinoviruses, in particular from the minor receptor group. The main structural differences between HRV2 and other rhinoviruses, including the minor receptor group serotype HRV1A, are located at the internal protein shell surface and at the external antigenic sites. In the interior, the N termini of VP1 and VP4 form a three-stranded beta-sheet in an arrangement similar to that present in poliovirus, although myristate was not visible at the amino terminus of VP4 in the HRV2 structure. The betaE-betaF loop of VP2, a linear epitope within antigenic site B recognized by monoclonal antibody 8F5, adopts a conformation considerably different from that found in the complex of 8F5 with a synthetic peptide of the same sequence. This either points to considerable structural changes impinged on this loop upon antibody binding, or to the existence of more than one single conformation of the loop when the virus is in solution. The hydrophobic pocket of VP1 was found to be occupied by a pocket factor apparently identical with that present in the major receptor group virus HRV16. Electron density, consistent with the presence of a viral RNA fragment, is seen stacked against a conserved tryptophan residue. Structure of human rhinovirus serotype 2 (HRV2).,Verdaguer N, Blaas D, Fita I J Mol Biol. 2000 Jul 28;300(5):1179-94. PMID:10903863[17] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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