Structural highlights
Function
GAG_HV2BE Mediates, with Gag-Pol polyprotein, the essential events in virion assembly, including binding the plasma membrane, making the protein-protein interactions necessary to create spherical particles, recruiting the viral Env proteins, and packaging the genomic RNA via direct interactions with the RNA packaging sequence (Psi).[UniProtKB:P04591] Targets the polyprotein to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus (By similarity). Matrix protein is part of the pre-integration complex. Implicated in the release from host cell mediated by Vpu. Binds to RNA (By similarity).[UniProtKB:P12493] Forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion (By similarity). Most core are conical, with only 7% tubular (By similarity). The core is constituted by capsid protein hexamer subunits (By similarity). The core is disassembled soon after virion entry (By similarity). Host restriction factors such as TRIM5-alpha or TRIMCyp bind retroviral capsids and cause premature capsid disassembly, leading to blocks in reverse transcription (By similarity). Capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species (By similarity). Host PIN1 apparently facilitates the virion uncoating (By similarity). On the other hand, interactions with PDZD8 or CYPA stabilize the capsid (By similarity). The capsid interacts with high affinity with human NONO, promoting detection of viral DNA by CGAS, leading to CGAS-mediated inmmune activation (PubMed:30270045).[UniProtKB:P04591][UniProtKB:P12493] Encapsulates and protects viral dimeric unspliced genomic RNA (gRNA). Binds these RNAs through its zinc fingers. Acts as a nucleic acid chaperone which is involved in rearangement of nucleic acid secondary structure during gRNA retrotranscription. Also facilitates template switch leading to recombination. As part of the polyprotein, participates in gRNA dimerization, packaging, tRNA incorporation and virion assembly.[UniProtKB:P04591] Plays a role in budding of the assembled particle by interacting with the host class E VPS proteins TSG101 and PDCD6IP/AIP1.[UniProtKB:P12493]
