6y9z
From Proteopedia
Structure of the native full-length HIV-1 capsid protein in complex with Cyclophilin A from helical assembly (-13,9)
Structural highlights
FunctionGAG_HV1H2 Matrix protein p17 targets Gag and Gag-Pol polyproteins to the plasma membrane via a multipartite membrane binding signal, that includes its myristoylated N-terminus. Also mediates nuclear localization of the preintegration complex. Implicated in the release from host cell mediated by Vpu. Capsid protein p24 forms the conical core of the virus that encapsulates the genomic RNA-nucleocapsid complex. Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. p6-gag plays a role in budding of the assembled particle by interacting with the host class E VPS proteins TSG101 and PDCD6IP/AIP1 (By similarity). Publication Abstract from PubMedThe mature retrovirus capsid consists of a variably curved lattice of capsid protein (CA) hexamers and pentamers. High-resolution structures of the curved assembly, or in complex with host factors, have not been available. By devising cryo-EM methodologies for exceedingly flexible and pleomorphic assemblies, we have determined cryo-EM structures of apo-CA hexamers and in complex with cyclophilin A (CypA) at near-atomic resolutions. The CA hexamers are intrinsically curved, flexible and asymmetric, revealing the capsomere and not the previously touted dimer or trimer interfaces as the key contributor to capsid curvature. CypA recognizes specific geometries of the curved lattice, simultaneously interacting with three CA protomers from adjacent hexamers via two noncanonical interfaces, thus stabilizing the capsid. By determining multiple structures from various helical symmetries, we further revealed the essential plasticity of the CA molecule, which allows formation of continuously curved conical capsids and the mechanism of capsid pattern sensing by CypA. Intrinsic curvature of the HIV-1 CA hexamer underlies capsid topology and interaction with cyclophilin A.,Ni T, Gerard S, Zhao G, Dent K, Ning J, Zhou J, Shi J, Anderson-Daniels J, Li W, Jang S, Engelman AN, Aiken C, Zhang P Nat Struct Mol Biol. 2020 Aug 3. pii: 10.1038/s41594-020-0467-8. doi:, 10.1038/s41594-020-0467-8. PMID:32747784[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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