Final answer:
The TATA-binding protein (TBP) binds to the TATA box within the core promoter region, inserting phenylalanine and isoleucine residues to form a kink in DNA, aiding the initiation of transcription.
Step-by-step explanation:
Within the core promoter region, the TATA-binding protein (TBP) is crucial in forming the transcription initiation complex by binding to the DNA at the TATA box. The TATA box, with the consensus sequence of 5'-TATAAA-3', allows TBP to insert phenylalanine and isoleucine residues into the minor groove of the DNA, causing a distinct kink that facilitates the unwinding of DNA and the assembly of transcription factors and RNA polymerase II. This interaction initiates transcription by enabling access to the DNA strand that needs to be transcribed and is important for the regulation of gene expression.