SEQUENCES IN THE HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 U3 REGION REQUIRED FOR IN-VIVO AND IN-VITRO INTEGRATION

A series of mutants with alterations in the U3 region of the human imm unodeficiency virus type 1 long terminal repeat were made, and the eff ects of these mutations were evaluated both in vitro and in vivo. When the subterminal 6 to 8 nucleotides of the U3 long terminal repeat wer e mutated, the resulting provirus was unable to efficiently replicate in vivo, and a mutant oligonucleotide which mimicked the mutation coul d not be efficiently cleaved but could be joined to target DNA by wild -type recombinant integrase protein in vitro. These results suggest th at this region is important in the specific recognition of the viral D NA by the integrase protein.