Editing Transcription factor (section)

=== Mechanistic ===

There are two mechanistic classes of transcription factors:
* [[General transcription factor]]s are involved in the formation of a [[Transcription preinitiation complex|preinitiation complex]]. The most common are abbreviated as [[TFIIA]], [[TFIIB]], [[TFIID]], [[TFIIE]], [[TFIIF]], and [[TFIIH]]. They are ubiquitous and interact with the core promoter region surrounding the transcription start site(s) of all [[class II gene]]s.<ref name="pmidc">{{Cite journal |vauthors=Orphanides G, Lagrange T, Reinberg D |date=November 1996 |title=The general transcription factors of RNA polymerase II |journal=Genes & Development |volume=10 |issue=21 |pages=2657–83 |doi=10.1101/gad.10.21.2657 |pmid=8946909 |doi-access=free}}</ref>
* '''Upstream transcription factors''' are proteins that bind somewhere upstream of the initiation site to stimulate or repress transcription. These are roughly synonymous with '''specific transcription factors''', because they vary considerably depending on what [[recognition sequence]]s are present in the proximity of the gene.<ref name="boron125-126">{{Cite book |title=Medical Physiology: A Cellular And Molecular Approaoch |vauthors=Boron WF |publisher=Elsevier/Saunders |year=2003 |isbn=1-4160-2328-3 |pages=125–126}}</ref>

{|class="wikitable"
!colspan=4| Examples of specific transcription factors<ref name="boron125-126" />
|-
! Factor !! Structural type !! [[Recognition sequence]] !! Binds as
|-
! [[Sp1 transcription factor|SP1]]
| [[Zinc finger]] || [[five prime end|5']]-GGGCGG-[[three prime end|3']] || Monomer
|-
! [[AP-1 transcription factor|AP-1]]
| [[Basic zipper]] || 5'-TGA(G/C)TCA-3' || Dimer
|-
! [[Ccaat-enhancer-binding proteins|C/EBP]]
| [[Basic zipper]] || 5'-ATTGCGCAAT-3' || Dimer
|-
! [[Heat shock factor]]
| [[Basic zipper]] || 5'-XGAAX-3' || Trimer
|-
! [[ATF/CREB]]
| [[Basic zipper]] || 5'-TGACGTCA-3' || Dimer
|-
! [[Myc|c-Myc]]
| [[Basic helix-loop-helix]]
| 5'-CACGTG-3' || Dimer
|-
! [[POU2F1|Oct-1]]
| [[Helix-turn-helix]] || 5'-ATGCAAAT-3' || Monomer
|-
! [[Nuclear factor 1|NF-1]]
| Novel || 5'-TTGGCXXXXXGCCAA-3' || Dimer
|-
|colspan=4| (G/C) = G or C <br /> X = [[adenine|A]], [[thymine|T]], [[guanine|G]] or [[cytosine|C]]
|}