Processing sites in the human immunodeficiency virus type 1 (HIV-1) Gag-Pro-Pol precursor are cleaved by the viral protease at different rates.
We have examined the kinetics of processing of the HIV-1 Gag-Pro-Pol precursor in an in vitro assay with mature protease added in trans. The processing sites were cleaved at different rates to produce distinct intermediates. The initial cleavage occurred at the p2/NC site. Intermediate cleavages occurred at similar rates at the MA/CA and RT/IN sites, and to a lesser extent at sites upstream of RT. Late cleavages occurred at the sites flanking the protease (PR) domain, suggesting sequestering of these sites. We observed paired intermediates indicative of half- cleavage of RT/RH site, suggesting that the RT domain in Gag-Pro-Pol was in a dimeric form under these assay conditions. These results clarify our understanding of the processing kinetics of the Gag-Pro-Pol precursor and suggest regulated cleavage. Our results further suggest that early dimerization of the PR and RT domains may serve as a regulatory element to influence the kinetics of processing within the Pol domain.
Pettit
Steve C
SC
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA. stpettit@yahoo.com
Lindquist
Jeffrey N
JN
Kaplan
Andrew H
AH
Swanstrom
Ronald
R
D019281:Dimerization; D015685:Fusion Proteins, gag-pol / Q000737:chemistry / Q000378:metabolism*; D016333:HIV Protease / Q000502:physiology*; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D019065:Virus Assembly
D015685:Fusion Proteins, gag-pol; D011498:Protein Precursors; D016333:HIV Protease