The locations of the key cis-acting DNA elements within –286PB are shown. TS1, TS2, TATA box, and a putative CATT box are boxed. The potential Oct-1, C-jun, and NF-1 binding sites in –286PB promoter are marked with big arrows. The directions of the arrows indicate the sense or the antisense strand that matched the consensus sequence. ARBS-1 and ARBS-2 are up-lined. The lowercase c (small arrow) is the transcription initiation site (Tis) of the PB gene.