Explain the key role of TATAboxbinding protein TBP in assemb

Explain the key role of TATA-box-binding protein (TBP) in assembling active TFII transcription complexes. Describe the role of phosphorylation of the C-terminal domain (CTD) of RNA polymerase II. Draw the reaction mechanisms that are catalyzed by the spliceosome.

Solution

1. The TATA binding protein (TBP) is a basic transcription factor that binds specifically to a DNA sequence called the TATA box. This sequence is 30 base pair upstream of the transcription start site in some eukaryotic gene promoters.

Role as a transcription factor: TBP is a subunit of the eukaryotic transcription factor TFIID. TFIID is the first protein to bind with the DNA during the formation of pre-initiation transcription complex of RNA polymerase II. Binding of TFIID to TATA box in the promoter region of the gene initiate the recruitment of other factors require for RNA polymerase to start transcription.

2. Role of phosphorylation of C-terminal Domain of RNA polymerase II: The main roles are listed below:

a. It functions a phosphorylation dependent splicing activator in a heterologous protein.

b. It coordinates transcription and RNA processing.