TFIIB recognition element (BRE), TATA element (box), initiation codon (Inr), downstream promoter element (DPE)

Proximal element of promoter, upstream activator sequence, enhancer, silencer, boundary element, insulator

The TATA element of the promoter is recognized by TFIIID and combined into TBP, distorting the DNA

The TBP-DNA complex platform recruits other general transcription factors and polymerases, among which TFⅡA, TFⅡBⅡ, and TFⅡF together with the polymerase, followed by TFⅡE, TFⅡH

Polymerase phosphorylation occurs during promoter escape

Pol II sheds most of the initiation factors, such as general transcription factors and mediator proteins

Recruit elongation factors, such as hSPT5, TFIIS (with proofreading function), ELL family (inhibit transient pauses)

The polymerase initially binds to the promoter to form a closed complex

Closed complex transforms into open complex

Promoter escape—abortive initiation

Mediates the binding of polymerase to the promoter, converting the core enzyme into a form that only initiates transcription at the promoter - RNA polymerase holoenzyme

The UP element is not recognized by delta factors and provides additional interactions to enhance polymerase binding to the promoter.

Proofreading while compositing

Proofreading function

Rho-independent

Rho-dependent