TATA Box Transcription Factor Research Articles

Yeast TATA-box transcription factor gene.

The first step in the transcription of most protein-encoding genes in eukaryotes is the binding of a transcription factor to the TATA-box promoter element. This TATA-box transcription factor was purified from extracts of the yeast Saccharomyces cerevisiae by using reconstitution of in vitro transcription reactions as an assay. The activity copurified with a protein whose sodium dodecyl sulfate/polyacrylamide gel mobility is 25 kDa. The sequence of the amino-terminal 21 residues of this protein was determined by sequential Edman degradation. A yeast genomic library was screened with mixed oligonucleotides encoding six residues of the protein sequence. The yeast TATA-box factor gene was cloned, and DNA sequencing revealed a 720-base-pair open reading frame encoding a 27,016-Da protein. The identity of the clone was confirmed by expressing the gene in Escherichia coli and detecting TATA-box factor DNA binding and transcriptional activities in extracts of the recombinant E. coli. The TATA-box factor gene was mapped to chromosome five of S. cerevisiae. RNA blot hybridization and nuclease S1 analysis indicated that the major TATA-box factor mRNA is 1.3 kilobases, including an unusually long 5' untranslated region of 188 +/- 5 nucleotides. Homology searches showed a region of distant similarity to the calcium-binding structures of calpains, a structure that has a conformation similar to the helix-turn-helix motif of DNA binding proteins.

A TATA box implicated in E1A transcriptional activation of a simple adenovirus 2 promoter.

Adenovirus E1A proteins stimulate transcription by RNA polymerases II and III from many promoters. The detailed mechanism of transcriptional activation (transactivation) by E1A proteins remains unclear, but genetic and biochemical results suggest that E1A products might act to stimulate the activity of cellular transcription factors. In this study, a detailed mutational analysis of the adenovirus E1B promoter was undertaken to define the DNA sequences required for proper basal transcription and E1A transactivation. Two key findings emerged: first the E1B promoter is an unusually simple RNA polymerase II promoter requiring only two sequence elements for proper regulation, the TATA box and a binding site for transcription factor Sp1; and second only mutations in the TATA box interfere with E1A-transactivation, suggesting that E1A mediates its effect on this promoter through the TATA-box transcription factor.