Genomic structure of the putative BTF3 transcription factor.

On the basis of the amino acid (aa) sequence of the putative BTF3 transcription factor, two complementary DNAs coding for the two proteins, BTF3a and BTF3b, have been cloned from a HeLa cell cDNA library. The two proteins are identical, except that BTF3b lacks the first 44 N-terminal aa present in BTF3a. These proteins originate from the same gene, which contains seven exons, and are the products of alternative splicing. The promoter region, containing a putative TATA box(es) and a CAAT box sequence, was identified. In addition, three other BTF3-like genes were characterized.