FIG. 1.

Mutations in the PPT affect viral titer. The left column shows the name of the different PPT mutants; the middle column shows the sequences. The top row shows the sequence of the wild-type PPT. The boxes containing stripes designate the nucleotides that deviate from traditional Watson-Crick base pairing in the crystal structure of HIV-1 RT in a complex with an RNA/DNA duplex derived from the PPT. Transversion mutations (A to C) were introduced into the 5′ end of the HIV-1 PPT. The mutated bases are shown in boldface. Virions containing these mutant PPTs were generated as described in Materials and Methods. The effects of the mutations on the relative virus titer (normalized to p24) are shown in the rightmost column. The relative titer was determined by averaging at least two independent experiments for each mutant.