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 (By similarity). 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). Capsid protein p30 forms the spherical core of the virion that encapsulates the genomic RNA-nucleocapsid complex. Nucleocapsid protein p10 is involved in the packaging and encapsidation of two copies of the genome. Binds with high affinity to conserved elements within the packaging signal, located near the 5'-end of the genome. This binding is dependent on genome dimerization (By similarity). Capsid protein p30 is a homohexamer, that further associates as homomultimer. The virus core is composed of a lattice formed from hexagonal rings, each containing six capsid monomers (By similarity). Late-budding domains (L domains) are short sequence motifs essential for viral particle budding. They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins. RNA-binding phosphoprotein p12 contains one L domain: a PPXY motif which potentially interacts with the WW domain 3 of NEDD4 E3 ubiquitin ligase. Matrix protein p15 contains one L domain: a PTAP/PSAP motif, which potentially interacts with the UEV domain of TSG101 (By similarity). Specific enzymatic cleavages by the viral protease yield mature proteins. The protease is released by autocatalytic cleavage. The polyprotein is cleaved during and after budding, this process is termed maturation (By similarity).