5mjv
Rebuild and re-refined model for Human Parechovirus 1
Structural highlights
FunctionPOLG_HPE1H Capsid proteins VP0, VP2, VP3 form a closed capsid enclosing the viral positive strand RNA genome. Capsid proteins interact with host alpha-V/beta-3 integrin heterodimer to provide virion attachment target cell. This attachment induces virion internalization predominantly through clathrin-mediated endocytosis.[1] Protein 2A: Is not a protease. Protein 2B: Affects membrane integrity and cause an increase in membrane permeability. 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. Protease 3C: 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 cooperatively to the protease (By similarity). RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals.[PROSITE-ProRule:PRU00539] Publication Abstract from PubMedAssembly of the major viral pathogens of the Picornaviridae family is poorly understood. Human parechovirus 1 is an example of such viruses that contains 60 short regions of ordered RNA density making identical contacts with the protein shell. We show here via a combination of RNA-based systematic evolution of ligands by exponential enrichment, bioinformatics analysis and reverse genetics that these RNA segments are bound to the coat proteins in a sequence-specific manner. Disruption of either the RNA coat protein recognition motif or its contact amino acid residues is deleterious for viral assembly. The data are consistent with RNA packaging signals playing essential roles in virion assembly. Their binding sites on the coat proteins are evolutionarily conserved across the Parechovirus genus, suggesting that they represent potential broad-spectrum anti-viral targets.The mechanism underlying packaging of genomic RNA into viral particles is not well understood for human parechoviruses. Here the authors identify short RNA motifs in the parechovirus genome that bind capsid proteins, providing approximately 60 specific interactions for virion assembly. Genomic RNA folding mediates assembly of human parechovirus.,Shakeel S, Dykeman EC, White SJ, Ora A, Cockburn JJ, Butcher SJ, Stockley PG, Twarock R Nat Commun. 2017 Dec;8(1):5. doi: 10.1038/s41467-016-0011-z. Epub 2017 Feb 23. PMID:28232749[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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