5i4t
From Proteopedia
Immature hexagonal lattice of HIV-1 Gag
Structural highlights
FunctionQ72497_9HIV1 Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex (By similarity). Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers (By similarity).[SAAS:SAAS012344_004_011858] Publication Abstract from PubMedVirus assembly and maturation proceed through the programmed operation of molecular switches, which trigger both local and global structural rearrangements to produce infectious particles. HIV-1 contains an assembly and maturation switch that spans the C-terminal domain (CTD) of the capsid (CA) region and the first spacer peptide (SP1) of the precursor structural protein, Gag. The crystal structure of the CTD-SP1 Gag fragment is a goblet-shaped hexamer in which the cup comprises the CTD and an ensuing type II beta-turn, and the stem comprises a 6-helix bundle. The beta-turn is critical for immature virus assembly and the 6-helix bundle regulates proteolysis during maturation. This bipartite character explains why the SP1 spacer is a critical element of HIV-1 Gag but is not a universal property of retroviruses. Our results also indicate that HIV-1 maturation inhibitors suppress unfolding of the CA-SP1 junction and thereby delay access of the viral protease to its substrate. Crystal structure of an HIV assembly and maturation switch.,Wagner JM, Zadrozny KK, Chrustowicz J, Purdy MD, Yeager M, Ganser-Pornillos BK, Pornillos O Elife. 2016 Jul 14;5. pii: e17063. doi: 10.7554/eLife.17063. PMID:27416583[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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