1u6p
From Proteopedia
NMR Structure of the MLV encapsidation signal bound to the Nucleocapsid protein
Structural highlights
Function[GAG_MLVMS] Gag polyprotein plays a role in budding and is processed by the viral protease during virion maturation outside the cell. During budding, it recruits, in a PPXY-dependent or independent manner, Nedd4-like ubiquitin ligases that conjugate ubiquitin molecules to Gag, or to Gag binding host factors. Interaction with HECT ubiquitin ligases probably link the viral protein to the host ESCRT pathway and facilitate release.[1] Matrix protein p15 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 (By similarity).[2] Capsid protein p30 forms the spherical core of the virion that encapsulates the genomic RNA-nucleocapsid complex (By similarity).[3] Nucleocapsid protein p10 is involved in the packaging and encapsidation of two copies of the genome. Binds with high affinity to conserved UCUG elements within the packaging signal, located near the 5'-end of the genome. This binding is dependent on genome dimerization.[4] 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 PubMedAll retroviruses specifically package two copies of their genomes during virus assembly, a requirement for strand-transfer-mediated recombination during reverse transcription. Genomic RNA exists in virions as dimers, and the overlap of RNA elements that promote dimerization and encapsidation suggests that these processes may be coupled. Both processes are mediated by the nucleocapsid domain (NC) of the retroviral Gag polyprotein. Here we show that dimerization-induced register shifts in base pairing within the Psi-RNA packaging signal of Moloney murine leukaemia virus (MoMuLV) expose conserved UCUG elements that bind NC with high affinity (dissociation constant = 75 +/- 12 nM). These elements are base-paired and do not bind NC in the monomeric RNA. The structure of the NC complex with a 101-nucleotide 'core encapsidation' segment of the MoMuLV Psi site reveals a network of interactions that promote sequence- and structure-specific binding by NC's single CCHC zinc knuckle. Our findings support a structural RNA switch mechanism for genome encapsidation, in which protein binding sites are sequestered by base pairing in the monomeric RNA and become exposed upon dimerization to promote packaging of a diploid genome. Structural basis for packaging the dimeric genome of Moloney murine leukaemia virus.,D'Souza V, Summers MF Nature. 2004 Sep 30;431(7008):586-90. PMID:15457265[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Mlvmo | Souza, V D | Summers, M F | A-c mismatch | A-minor k-turn | Bulge | G-a mismatch | G-u mismatch | Mlv | Nc | Stem loop | U-u mismatch | Viral protein-rna complex | Zinc finger
