2r02
Crystal Structure of ALIX/AIP1 in complex with the HIV-1 YPLTSL Late DomainCrystal Structure of ALIX/AIP1 in complex with the HIV-1 YPLTSL Late Domain
Structural highlights
Function[PDC6I_HUMAN] Class E VPS protein involved in concentration and sorting of cargo proteins of the multivesicular body (MVB) for incorporation into intralumenal vesicles (ILVs) that are generated by invagination and scission from the limiting membrane of the endosome. Binds to the phospholipid lysobisphosphatidic acid (LBPA) which is abundant in MVBs internal membranes. The MVB pathway appears to require the sequential function of ESCRT-O, -I,-II and -III complexes. The ESCRT machinery also functions in topologically equivalent membrane fission events, such as the terminal stages of cytokinesis and enveloped virus budding (HIV-1 and other lentiviruses). Appears to be an adapter for a subset of ESCRT-III proteins, such as CHMP4, to function at distinct membranes. Required for completion of cytokinesis. Involved in HIV-1 virus budding. Can replace TSG101 it its role of supporting HIV-1 release; this function implies the interaction with CHMP4B. May play a role in the regulation of both apoptosis and cell proliferation.[1] [2] [3] [4] [5] [6] [GAG_HV1S9] 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 (By similarity). 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). 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). 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 PubMedRetrovirus budding requires short peptide motifs (late domains) located within the viral Gag protein that function by recruiting cellular factors. The YPX(n)L late domains of HIV and other lentiviruses recruit the protein ALIX (also known as AIP1), which also functions in vesicle formation at the multivesicular body and in the abscission stage of cytokinesis. Here, we report the crystal structures of ALIX in complex with the YPX(n)L late domains from HIV-1 and EIAV. The two distinct late domains bind at the same site on the ALIX V domain but adopt different conformations that allow them to make equivalent contacts. Binding studies and functional assays verified the importance of key interface residues and revealed that binding affinities are tuned by context-dependent effects. These results reveal how YPX(n)L late domains recruit ALIX to facilitate virus budding and how ALIX can bind YPX(n)L sequences with both n = 1 and n = 3. Structural and functional studies of ALIX interactions with YPX(n)L late domains of HIV-1 and EIAV.,Zhai Q, Fisher RD, Chung HY, Myszka DG, Sundquist WI, Hill CP Nat Struct Mol Biol. 2008 Jan;15(1):43-9. Epub 2007 Dec 9. PMID:18066081[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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