Functionally conserved E2F1 binding sites in human and mouse genes. (a) Schematic alignment of functionally conserved E2F1 binding sites between human (hs) and mouse (mm) promoter sequences from between-TFBS distance of 20 bp. Also listed are the numbers of conserved E2F1 binding site(s) detected by phylogenetic footprinting (PF). Asterisks indicate promoters of genes with experimentally proven E2F1 binding sites. (b) Sequence alignment of synergistic E2F1 binding sites from the E2F1 gene and two E2F1 binding site clusters from the ACVR1 gene. Core motifs are shown in upper case letters, and the distances between adjacent binding sites are shown in brackets. Also shown are the locations of each binding site in relation to the transcription start site.