TATA-Binding Protein: Difference between revisions

== Exploring the Structure ==

TATA-binding protein uses two types of interactions to recognize and hold the TATA sequence, as seen in this structure [[1ytb]]. First, as shown at the top, it has a string of lysine and arginine amino acids (colored dark blue) that interact with the <scene name='TATA-Binding_Protein/1ytb/2'>phosphate groups of the DNA</scene>. This glues the <scene name='TATA-Binding_Protein/1ytb/7'>protein</scene> to the <scene name='TATA-Binding_Protein/1ytb/6'>DNA</scene>. Second, the protein uses specially-placed amino acids to interact with DNA bases. <scene name='TATA-Binding_Protein/1ytb/8'>four phenylalanine amino acids</scene> jam into the DNA minor groove and form the kinks that bend the DNA. There are also <scene name='TATA-Binding_Protein/1ytb/9'> two symmetrical asparagine amino acids </scene> that form hydrogen bonds at the very center. The combination of the unusual flexibility of TATA DNA sequences and these specific hydrogen bonds allows TATA-binding protein to recognize the proper sequence.

As you are looking at these structures yourself, notice that TATA-binding protein, even though it is composed of a single protein chain, is <scene name='TATA-Binding_Protein/1ytb/10'> composed of two symmetrical halves </scene> . This symmetry is easily seen in the two pairs of phenylalanines and the two asparagines. It is thought that an ancient gene duplication created this protein by combining two copies of the same gene.  

==  Acknowledgements ==

*Content adapted from David S. Goodsell and Shuchismita Dutta's Molecule of the Month on Zinc Fingers http://mgl.scripps.edu/people/goodsell/pdb/pdb67