LTR promoter organization of HIV-1 subtypes A through G.

Most experimental evidence for protein binding sites has been provided for the LTR of HIV-1 subtype B. Furthermore, recent evidence supports the conversion of the upstream NF-kB site of subtype E into a GABP binding site. The bold dark red box placed at -28 represents the TAAAA variant of the TATA canonical box present in subtype E. The upstream TATA box is indicated also as a bold red box, and the open boxes at this position indicate the position of the non-TATA sequence in the other subtypes. RBEIII, NFkB, Sp1, AP-1 and GABP motifs are shown. The hatched boxes represents overlapping motifs.