Book of Abstracts: Albany 2003
June 17-21 2003
In vivo and In vitro Self-association Interaction Studies on the N-terminal of Yeast Tata Binding Protein (TBP)
The yeast TATA binding protein TFIID (yTBP) is encoded by the gene SPT15 and is responsible for specific transcription in vivo. The TATA element is an essential component of many promoters transcribed by RNA polymerase II. The binding of the general transcription factor TBP to the TATA element is the first step in the pathway of transcription initiation. There is high conservation among eukaryotes in the function of TBP. It is a two-domain monomer of ~ 27 KDa and also, forms tetramers and octomers in vitro. The sequence of the carboxy-terminal domain is strongly conserved showing approximately 80% sequence identity while the N-terminal of TBP is highly divergent across species in both length (18-173 residues) and sequence. The DNA binding region of TBP is located in the C-terminal and little is known about the highly divergent N-terminal region of yTBP and about its role in the formation of dimers, octamers and tetramers and if it is associated with modulating the transcription mechanism as in vitro studies suggest. This study reports using an in vivo Escherichia coli two-hybrid system to determine if the N-terminal domain of TBP exhibits any self-association with N-terminal and/or with core. To date two-hybrid results are consistent with in vitro experiments using pull-down assays and cross-linking experiments, showing that N-terminal self-association, interaction occurs. Current experiments are examining N-terminal interactions with core and full length TBP and core with full length TBP.
Claire A. Adams
Department of Biochemistry