J Biol Chem, Vol. 274, Issue 33, 23203-23209, August 13, 1999
An Interaction between the N-terminal Region and the Core Domain
of Yeast TFIIB Promotes the Formation of TATA-binding Protein-TFIIB-DNA
Complexes
Chaitanya S.
Bangur,
Silviu L.
Faitar,
Jason P.
Folster, and
Alfred S.
Ponticelli
From the Department of Biochemistry and the Center for Advanced
Molecular Biology and Immunology, School of Medicine and Biomedical
Sciences, State University of New York, Buffalo, New
York 14214-3000
The general transcription factor IIB (TFIIB)
plays an essential role in transcription of protein-coding genes by
eukaryotic RNA polymerase II. We previously identified a yeast TFIIB
mutant (R64E) that exhibited increased activity in the formation of
stable TATA-binding protein-TFIIB-DNA (DB) complexes in
vitro. We report here that the homologous human TFIIB mutant
(R53E) also displayed increased activity in DB complex formation
in vitro. Biochemical analyses revealed that the increased
activity of the R64E mutant in DB complex formation was associated with
an altered protease sensitivity of the protein and an enhanced
interaction between the N-terminal region and the C-terminal core
domain. These results suggest that the intramolecular interaction in
yeast TFIIB stabilizes a productive conformation of the protein for the
association with promoter-bound TATA-binding protein.
Copyright © 1999 by The American Society for Biochemistry and Molecular Biology, Inc.