The TATA box is not enough: the structure and conservation of TATA box promoters

by

Borya Shakhnovich
Harvard University

Wednesday, August 1, 2007
1:00 p.m.
3-115 EE/CSci

The TATA binding protein (TBP) is necessary for transcriptional initiation in yeast. TBP can bind a promoter at a TATA consensus sequence, eventually leading to downstream gene expression. However, the presence of a TATA box in a promoter is not a major determinant of TBP binding leading to the conclusion that TBP recruitment is a multifaceted and complex. Thus, predicting TBP functionality from a promoter sequence remains challenging. Here, we identify promoter features that can be used to explain TBP sensitivity. Functional-TATA promoters are longer; avoid incorrectly placed TATA boxes; and are enriched in nucleosomes near the TATA box. Most strikingly, TATA promoters are GC rich in the extended promoter. All these promoter features are significantly conserved across the yeast phylogeny. Consequently, we show that functional-TATA promoters evolve slower than other TATA-containing promoters. Together, these results suggest that promoter architecture plays an important role in the regulation of TATA-box dependent transcription and places significant constraints on the evolution of promoter sequences.

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