FIG. 4.

Occurrence of CpG sites in 5′ LTRs belonging to the HERV-K(HML-2) and the HERV-K(OLD) families (see the text for details). HS consensus is a previously reported consensus sequence for human-specific HERV-K(HML-2) LTRs (7). The entire 5′ LTR sequence is shown for each LTR. Each sequence was analyzed for the presence of CpG sites (triangles), as well as apparently mutated CpG sites (X's). TATA boxes are furthermore indicated for each LTR, when they could be identified. For each LTR, the 5′-most 620 bp were analyzed. Note that HERV-K(OLD) 5′ LTRs frequently display mutated CpG sites, indicating former CpG methylation.