Promoter

Updated by Hongjiang on 09/20/2022

a | The traditional view of transcription initiation postulates that transcription initiates at gene core promoters, which recruit the transcription machinery, consisting of RNA polymerase II (Pol II) and general transcription factors (GTFs), thereby leading to the formation of the pre-initiation complex (PIC) and transcription initiation. Transcription from core promoters is activated by enhancers, which can be located distally and bind sequence-specific transcription factors (TF), which recruit cofactors (COF) that convey the activating cues to the PIC at the core promoter. b | Active enhancers exhibit divergent transcription of short, unstable enhancer RNAs (eRNAs) from two separate transcription start sites located at the edges of the nucleosome-depleted region (NDR) where the enhancer resides. c | Promoters produce long, stable mRNAs from a gene core promoter in the sense direction (orientation of the gene) and short, unstable upstream antisense RNAs (uaRNAs) from the upstream edge of an NDR that contains the transcription factor-bound proximal promoter. Separate PICs drive unidirectional transcription from each of the two TSSs.

(2018,NRMCB)Eukaryotic core promoters and the functional basis of transcription initiation

Transcription Factors(TF)

These trans-acting proteins(activator) are refered to as Transcription Fctors(TF), a group of trans-acting factors.

TATA

TATA-box consisting of roughly seven nucleotides of the sequence T–A–T–A–(A or T)–A–(A or T), located just upstream of the transcription initiation site.

As it attracts RNA polymerase only weakly on its own (without an enhancer), the TATA box allows a low, so-called basal level of transcription.