CRYSTAL-STRUCTURE OF TFIID TATA-BOX BINDING-PROTEIN

The structure of a central component of the eukaryotic transcriptional apparatus, a TATA-box binding protein (TBP or TFIIDtau) from Arabidopsis thaliana, has been determined by X-ray crystallography at 2.6 angstrom resolution. This highly symmetric alpha/beta structure contains a new DNA-binding fold, resembling a molecular 'saddle' that sits astride the DNA. The DNA-binding surface is a curved, antiparallel beta-sheet. When bound to DNA, the convex surface of the saddle would be presented for interaction with other transcription initiation factors and regulatory proteins.