2hrv
From Proteopedia
2A CYSTEINE PROTEINASE FROM HUMAN RHINOVIRUS 2
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 PubMedThe crystal structure of the 2A proteinase from human rhinovirus serotype 2 (HRV2-2A(pro)) has been solved to 1.95 A resolution. The structure has an unusual, although chymotrypsin-related, fold comprising a unique four-stranded beta sheet as the N-terminal domain and a six-stranded beta barrel as the C-terminal domain. A tightly bound zinc ion, essential for the stability of HRV2-2A(pro), is tetrahedrally coordinated by three cysteine sulfurs and one histidine nitrogen. The active site consists of a catalytic triad formed by His18, Asp35 and Cys106. Asp35 is additionally involved in an extensive hydrogen-bonding network. Modelling studies reveal a substrate-induced fit that explains the specificity of the subsites S4, S2, S1 and S1'. The structure of HRV2-2A(pro) suggests the mechanism of the cis cleavage and its release from the polyprotein. The structure of the 2A proteinase from a common cold virus: a proteinase responsible for the shut-off of host-cell protein synthesis.,Petersen JF, Cherney MM, Liebig HD, Skern T, Kuechler E, James MN EMBO J. 1999 Oct 15;18(20):5463-75. PMID:10523291[17] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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