TATABinding

TATAbinding, usually called TATA-binding protein (TBP), is a general transcription factor that binds specifically to the TATA box within promoter DNA and serves as a core component of the transcription factor complex TFIID in eukaryotes. By recognizing the TATA consensus sequence and bending the DNA, TBP helps recruit the RNA polymerase II machinery to initiate transcription.

TBP is highly conserved across eukaryotes and archaea. The C-terminal core of TBP forms a saddle-like structure that binds the minor groove of DNA, while the N-terminal region is more variable and influences interactions with other proteins. In many organisms, TBP-like proteins (TBPL1 and TBPL2/TRF2) can substitute for TBP at selected promoters, enabling promoter-specific transcription programs.

TBP is encoded by the TBP gene. It is a central component of TFIID and functions together with TBP-associated factors (TAFs) to assemble the pre-initiation complex on promoters. The TBP-DNA complex induces a sharp bend, facilitating recruitment of RNA polymerase II and general transcription factors.

Genetic variation in TBP can have clinical consequences. In humans, expansions in the polyglutamine-encoding region of the TBP gene cause spinocerebellar ataxia type 17 (SCA17), illustrating how TBP dysfunction or altered dosage can contribute to neurodegenerative disease. TBP function is also regulated by interaction networks and chromatin state, linking it to development and disease-related changes in gene expression.