The false statement is: (a) Transcriptional regulators usually interact with the sugar–phosphate backbone on the outside of the double helix to determine which DNA sequence to bind.
Transcriptional regulator or factor is protein with the ability to control and regulate gene expression at the transcription level by binding to DNA. Transcriptional factors have domain-DNA-binding domain which contains structural motif that recognizes DNA and it is responsible for the attachment to specific DNA sequence. It usually binds to the DNA major groove (hydrogen bonding) because it is less degenerate than that of the DNA minor groove.
Transcriptional factors also contain trans-activating domain for the binding of other proteins and signal-sensing domain for the detection of external signals.
