3ddk | pdb_00003ddk
Coxsackievirus B3 3Dpol RNA Dependent RNA Polymerase
Structural highlights
Function[Q66338_9ENTO] Protein 2C associates with and induces structural rearrangements of intracellular membranes. It displays RNA-binding, nucleotide binding and NTPase activities (By similarity).[SAAS:SAAS001676_004_016611] 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).[SAAS:SAAS000199_004_042266] RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals (By similarity).[SAAS:SAAS001676_004_010047] 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 coxsackievirus B3 polymerase has been solved at 2.25-A resolution and is shown to be highly homologous to polymerases from poliovirus, rhinovirus, and foot-and-mouth disease viruses. Together, these structures highlight several conserved structural elements in picornaviral polymerases, including a proteolytic activation-dependent N-terminal structure that is essential for full activity. Interestingly, a comparison of all of the picornaviral polymerase structures shows an unusual conformation for residue 5, which is always located at a distortion in the beta-strand composed of residues 1 to 8. In our earlier structure of the poliovirus polymerase, we attributed this conformation to a crystal packing artifact, but the observation that this conformation is conserved among picornaviruses led us to examine the role of this residue in further detail. Here we use coxsackievirus polymerase to show that elongation activity correlates with the hydrophobicity of residue 5 and, surprisingly, more hydrophobic residues result in higher activity. Based on structural analysis, we propose that this residue becomes buried during the nucleotide repositioning step that occurs prior to phosphoryl transfer. We present a model in which the buried N terminus observed in all picornaviral polymerases is essential for stabilizing the structure during this conformational change. Crystal structure of coxsackievirus B3 3Dpol highlights the functional importance of residue 5 in picornavirus polymerases.,Campagnola G, Weygandt M, Scoggin K, Peersen O J Virol. 2008 Oct;82(19):9458-64. Epub 2008 Jul 16. PMID:18632862[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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