Role of the SP2 Domain and Its Proteolytic Cleavage in HIV-1 Structural Maturation and Infectivity

摘要: HIV-1 buds as an immature, noninfectious virion. Proteolysis of its main structural component, Gag, is required for morphological maturation and infectivity leads to release four functional domains the spacer peptides SP1 SP2. The N-terminal cleavages Gag separation from CA are all essential viral infectivity, while roles two C-terminal role SP2, separating NC p6 domains, less well defined. We have analyzed variants with defective cleavage at either or both sites flanking largely lacking regarding virus production, maturation. Neither presence nor proteolytic processing SP2 was particle release. Viral almost abolished when were severely reduced fast site between defective. This correlated increased proportion irregular core structures observed by cryo-electron tomography, although unaffected. Mutation slow deletion most had only a minor effect on did not induce major alterations in mature morphology. speculate that but also kinetics this region successful maturation, itself dispensable.