Table 1.

Yeast general transcription factors

FactoraMass (kDa)Gene(s)EssentialCharacteristicsMetazoan homolog(s)Reference(s)
TBP (factor d)27SPT15YesBinds TATA element; nucleates PIC assembly; recruits TFIIBTBP124, 177
TFIIB (factor e)38SUA7YesStabilizes TATA-TBP interaction; recruits RNA pol II-TFIIF; affects start site selection; zinc ribbonTFIIB366
TFIIF (factor g)82TFG1, SSU71YesFacilitates RNA pol II-promoter targeting; stimulates elongation; functional interaction with TFIIBRAP74196, 459
47TFG2Yesς factor homology; destabilizes nonspecific RNA pol II-DNA interactionsRAP30196
27TFG3, ANC1, SWP29,TAF30NoCommon subunit of TFIID, TFIIF, and the SWI/SNF complexAF-9, ENL55, 196, 531
TFIIE (factor a)66TFA1YesRecruits TFIIH; stimulates TFIIH catalytic activities; functions in promoter melting and clearance; zinc binding domainTFIIE-α133
43TFA2YesTFIIE-β133
TFIIHb (factor b)95SSL2, RAD25YesFunctions in promoter melting and clearance; ATP-dependent DNA helicase (3′ → 5′); DNA-dependent ATPase; ATPase/helicase required for both transcription and NERXPB, ERCC3169
85RAD3YesATP-dependent DNA helicase (5′ → 3′); DNA-dependent ATPase; ATPase/helicase required for NER but not transcriptionXPD, ERCC222, 171
73TFB1YesRequired for NERp62160
59TFB2YesRequired for NERp52134
50SSL1YesRequired for NER; zinc binding domainp44528, 553
47, 45CCL1YesTFIIK subcomplex with Kin28Cyclin H464
37TFB4Yesp34134
32TFB3YesZinc RING finger; links core-TFIIH with TFIIK; unlike Mat1, not a subunit of kinase/cyclin subcomplexMat1134
33KIN28YesTFIIK subcomplex with Ccl1MO15, Cdk7136, 499
  • a The initial designations of the yeast general transcription factors by Kornberg’s laboratory are denoted in parentheses.

  • b TFIIH is composed of core-TFIIH (Rad3, Ssl1, Tfb1 to Tfb4), plus Ssl2/Rad25 and the TFIIK kinase/cyclin subcomplex (Kin28, Ccl1).