A. The HIV-1 NC Zinc finger mutants. The sequence of HIV-1 NCp7 (1–55) is shown. Mutations H23C and H44C are indicated. Deletions ΔZF1 and ΔZF2 correspond to a complete deletion of the zinc fingers (ZF). ΔNC was described elsewhere . B. Gag expression and maturation in HeLaP4 cells. HelaP4 cells were transfected with the pNL4.3 DNA (wild-type or either one of the NC mutants) and subsequently harvested and lysed. Viral proteins were analyzed by SDS-PAGE and revealed by immunoblotting with anti-CAp24. Immunodetection of the Gag maturation products. Wild-type HIV-1 and NC mutants are indicated. Lanes "V" and "Cell" representing pelletable virions from culture medium and cell lysates, respectively. Pr55Gag, p41(MA-CA), p49(MA-CA-p2-NC) and CAp24/p25 are indicated by arrows.