Table 1.

Yeast general transcription factors

FactoraMass (kDa)Gene(s)EssentialCharacteristicsMetazoan homolog(s)Reference(s)
TBP (factor d)27 SPT15 YesBinds TATA element; nucleates PIC assembly; recruits TFIIBTBP 124,177
TFIIB (factor e)38 SUA7 YesStabilizes TATA-TBP interaction; recruits RNA pol II-TFIIF; affects start site selection; zinc ribbonTFIIB 366
TFIIF (factor g)82 TFG1, SSU71 YesFacilitates RNA pol II-promoter targeting; stimulates elongation; functional interaction with TFIIBRAP74 196, 459
47 TFG2 Yesς factor homology; destabilizes nonspecific RNA pol II-DNA interactionsRAP30 196
27 TFG3, ANC1, SWP29,TAF30 NoCommon subunit of TFIID, TFIIF, and the SWI/SNF complexAF-9, ENL 55, 196, 531
TFIIE (factor a)66 TFA1 YesRecruits TFIIH; stimulates TFIIH catalytic activities; functions in promoter melting and clearance; zinc binding domainTFIIE-α 133
43 TFA2 YesTFIIE-β 133
TFIIHb (factor b)95 SSL2, RAD25 YesFunctions in promoter melting and clearance; ATP-dependent DNA helicase (3′ → 5′); DNA-dependent ATPase; ATPase/helicase required for both transcription and NERXPB, ERCC3 169
85 RAD3 YesATP-dependent DNA helicase (5′ → 3′); DNA-dependent ATPase; ATPase/helicase required for NER but not transcriptionXPD, ERCC2 22, 171
73 TFB1 YesRequired for NERp62 160
59 TFB2 YesRequired for NERp52 134
50 SSL1 YesRequired for NER; zinc binding domainp44 528, 553
47, 45 CCL1 YesTFIIK subcomplex with Kin28Cyclin H 464
37 TFB4 Yesp34 134
32 TFB3 YesZinc RING finger; links core-TFIIH with TFIIK; unlike Mat1, not a subunit of kinase/cyclin subcomplexMat1 134
33 KIN28 YesTFIIK subcomplex with Ccl1MO15, Cdk7 136, 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).