♦Gag-Pol polyprotein (Pr160Gag-Pol) [Cleaved into: Matrix protein p17 (MA)
♦ Capsid protein p24 (CA)
♦ Spacer peptide 1 (SP1) (p2)
♦ Nucleocapsid protein p7 (NC)
♦ Transframe peptide (TF)
♦ p6-pol (p6*)
♦ Protease (EC 3.4.23.16) (PR) (Retropepsin)] (Fragment)

NC_001802.1 ;  AF033819.3 

MGARASVLSGGELDRWEKIRLRPGGKKKYKLKHIVWASRELERFAVNPSLLETSEGCRQILGQLQPSLQTGSEELKSLFNTVATLYCVHQRIEVKDTKEA
LEKIEEEQNKSKKKAQQAAADTGNSSKVSQNYPIVQNIQGQMVHQAISPRTLNAWVKVVEEKAFSPEVIPMFSALSEGATPQDLNTMLNTVGGHQAAMQM
LKETINEEAAEWDRLHPAQAGPIAPGQMREPRGSDIAGTTSTLQEQIGWMTSNPPIPVGEIYKRWIILGLNKIVRMYSPSSILDIRQGPKEPFRDYVDRF
YKTLRAEQASQEVKNWMTETLLVQNANPDCKTILKALGPAATLEEMMTACQGVGGPGHKARVLAEAMSQVTNSTTIMMQRGNFRNQRKIIKCFNCGKEGH
LARNCRAPRKKGCWKCGKEGHQMKDCNERQANFLREDLAFLQGKAREFSSEQTRANSPSRGELQVWGRDNNPLSEAGAERQGTVSFSFPQITLWQRPLVT
LKIGGQLKEALLDTGADDTVLEEMNSPGRWKP

♦Gag-Pol polyprotein: Mediates, with Gag 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). Gag-Pol polyprotein may regulate its own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, the polyprotein would promote translation, whereas at high concentration, the polyprotein would encapsidate genomic RNA and then shut off translation.
♦ Matrix protein p17: Targets the polyprotein to the plasma membrane via a multipartite membrane-binding signal, that includes its myristoylated N-terminus. Matrix protein is part of the pre-integration complex. Implicated in the release from host cell mediated by Vpu. Binds to RNA.
♦ Capsid protein p24: Forms the conical core that encapsulates the genomic RNA-nucleocapsid complex in the virion. Most core are conical, with only 7% tubular. The core is constituted by capsid protein hexamer subunits. 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. Capsid restriction by TRIM5 is one of the factors which restricts HIV-1 to the human species. Host PIN1 apparently facilitates the virion uncoating. On the other hand, interactions with PDZD8 or CYPA stabilize the capsid.
♦ Nucleocapsid protein p7: 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.
♦ Protease: Aspartyl protease that mediates proteolytic cleavages of Gag and Gag-Pol polyproteins during or shortly after the release of the virion from the plasma membrane. Cleavages take place as an ordered, step-wise cascade to yield mature proteins. This process is called maturation. Displays maximal activity during the budding process just prior to particle release from the cell. Also cleaves Nef and Vif, probably concomitantly with viral structural proteins on maturation of virus particles. Hydrolyzes host EIF4GI and PABP1 in order to shut off the capped cellular mRNA translation. The resulting inhibition of cellular protein synthesis serves to ensure maximal viral gene expression and to evade host immune response (By similarity).

♦ Gag-Pol polyprotein: Host cell membrane
♦ Lipid-anchor. Host endosome, host multivesicular body. Note=These locations are linked to virus assembly sites. The main location is the cell membrane, but under some circumstances, late endosomal compartments can serve as productive sites for virion assembly. .
♦ Matrix protein p17: Virion membrane
♦ Lipid-anchor . Host nucleus . Host cytoplasm .
♦ Capsid protein p24: Virion .
♦ Nucleocapsid protein p7: Virion .

DOMAIN 508 >532 Peptidase A2.

♦ACT_SITE 513 513 For protease activity
♦ shared with dimeric partner.