Taxonomic distribution of proteins containing TFIIA domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing TFIIA domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

A transcription reinitiation intermediate that is stabilized by activator.

Yudkovsky N, Ranish JA, Hahn S
Nature. 2000; 408: 225-9

High levels of gene transcription by RNA polymerase II depend on high rates oftranscription initiation and reinitiation. Initiation requires recruitment of thecomplete transcription machinery to a promoter, a process facilitated byactivators and chromatin remodelling factors. Reinitiation probably occursthrough a different pathway. After initiation, a subset of the transcriptionmachinery remains at the promoter, forming a platform for assembly of a secondtranscription complex. Here we describe the isolation of a reinitiationintermediate that includes transcription factors TFIID, TFIIA, TFIIH, TFIIE andMediator. This intermediate can act as a scaffold for formation of a functionalreinitiation complex. Formation of this scaffold is dependent on ATP and TFIIH.The scaffold is stabilized in the presence of the activator Gal4-VP16, but notGal4-AH, suggesting a new role for some activators and Mediator in promoting highlevels of transcription.

Crystal structure of a yeast TFIIA/TBP/DNA complex.

Tan S, Hunziker Y, Sargent DF, Richmond TJ
Nature. 1996; 381: 127-51

The X-ray crystal structure of the transcription factor IIA (TFIIA) in complexwith the TATA-box-binding protein (TBP) and TATA-element DNA is presented at 2.5 A resolution. TFIIA is composed of a beta-barrel and a four-helix bundle motifthat together have a boot-like appearance. The beta-barrel extends the TBPbeta-sheet and bridges over the DNA major groove immediately upstream of the TATAbox. The four-helix bundle contributes substantially to the surface of thecomplex available for interaction with additional transcription factors.

A single cDNA, hTFIIA/alpha, encodes both the p35 and p19 subunits of humanTFIIA.

DeJong J, Roeder RG
Genes Dev. 1993; 7: 2220-34

TFIIA is a transcription factor that, by interacting with the TATA-bindingsubunit (TBP) of TFIID, modulates transcription initiation by RNA polymerase IIin vitro. By use of a mobility shift assay, TFIIA was purified from HeLa cells asa complex of 35-, 19-, and 12-kD subunits. Oligonucleotides were used to isolate a human cDNA clone, hTFIIA/alpha, which encodes a 55-kD protein with homology to the product of the yeast gene TOA1. The open reading frame of hTFIIA/alphacontains peptide sequences obtained from both the p35 and p19 subunits of naturalhuman TFIIA, and thus encodes these two subunits. Consistent with this, antiserumraised against the 55-kD hTFIIA/alpha-encoded protein reacted with both the p35and p19 subunits of natural TFIIA, and the recombinant protein could functionallyreplace those subunits in a mobility shift assay with renatured p12. An efficientaffinity purification for natural human TFIIA was suggested by the sequence ofthe hTFIIA/alpha protein and demonstrated biochemically. Finally, transcriptionfrom the adenovirus major late promoter was greatly reduced in nuclear extractsdepleted with anti-TFIIA/alpha serum and was restored to original levels by thereaddition of purified human TFIIA.