1asv
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Avian sarcoma virus integrase catalytic core domain
Structural highlights
FunctionPOL_RSVSB Capsid protein p27: Self-associates to form the irregular polyhedron core composed of hexamers and pentamers, that encapsulates the genomic RNA-nucleocapsid complex. Assembles as a tube in vitro. Binds to inositol hexakisphosphate (IP6), which allows the assembly of the polyhedral capsid.[UniProtKB:P03322] Plays a role in the oligomerization of the Gag polyprotein and in the stabilization of the immature particle. Essential layering element during tube assembly. Allows the cooperative binging of Gag to the host plasma membrane.[UniProtKB:P03322] Binds strongly to viral nucleic acids and promotes their packaging (By similarity). Plays a role in the maturation-stabilization of the viral dimeric RNA via highly structured zinc-binding motifs (By similarity).[UniProtKB:P03322][UniProtKB:P0C776] The aspartyl protease mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell.[PROSITE-ProRule:PRU00275] Catalyzes viral DNA integration into the host chromosome, by performing a series of DNA cutting and joining reactions (PubMed:9218451). This recombination event is an essential step in the viral replication cycle. Has a strong preference for using the 3'-OH at the viral DNA end as a nucleophile.[UniProtKB:P03354][1] 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 PubMedRetroviral integrase (IN) functions to insert retroviral DNA into the host cell chromosome in a highly coordinated manner. IN catalyzes two biochemically separable reactions: processing of the viral DNA ends and joining of these ends to the host DNA. Previous studies suggested that these two reactions are chemically similar and are carried out by a single active site that is characterized by a highly conserved constellation of carboxylate residues, the D,D(35)E motif. We report here the crystal structure of the isolated catalytic domain of avian sarcoma virus (ASV) IN, solved using multiwavelength anomalous diffraction data for a selenomethionine derivative and refined at 1.7 A resolution. The protein is a crystallographic dimer with each monomer featuring a five-stranded mixed beta-sheet region surrounded by five alpha-helices. Based on the general fold and the arrangement of catalytic carboxylate residues, it is apparent that ASV IN is a member of a superfamily of proteins that also includes two types of nucleases, RuvC and RNase H. The general fold and the dimer interface are similar to those of the analogous domain of HIV-1 IN, whose crystal structure has been determined at 2.5 A resolution. However, the ASV IN structure is more complete in that all three critical carboxylic acids, Asp64, Asp121 and Glu157, are ordered. The ordered active site and the considerably higher resolution of the present structure are all important to an understanding of the mechanism of retroviral DNA integration, as well as for designing antiviral agents that may be effective against HIV. High-resolution structure of the catalytic domain of avian sarcoma virus integrase.,Bujacz G, Jaskolski M, Alexandratos J, Wlodawer A, Merkel G, Katz RA, Skalka AM J Mol Biol. 1995 Oct 20;253(2):333-46. PMID:7563093[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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