Table 2.

Yeast TBP derivatives

Amino acid replacement(s)RegionaFunctional defectReference(s)
N69SS1Selectively increases transcription from weak promoters; does not alter TBP-TATA affinity29
V71ES1Diminished DNA binding387
V71AS1Activation defective; diminished DNA binding9
R105CS3Diminished DNA binding387
P109A, P109QS3-S4 loopDiminished DNA binding; promoter-specific activation defects9
T112KS4Diminished DNA binding387
L114KS4Activation defective; impaired interaction with VP16248
L114FS4Altered DNA binding specificity10
F116YS4-S5 loopDiminished DNA binding9, 387
S118LS4-S5 loopActivation defective; diminished DNA binding275
K133L, K138LH2Eliminates TFIIA binding; temperature-sensitive growth defect suppressed by high-copy-number BRF1/TDS4/PCF445, 46
K133L, K145LH2Eliminates TFIIA binding46
K138T, Y139A (N2-1)H2Activation defective; eliminates TFIIA binding447
F148HInter-repeat strandActivation defective; normal interaction with TATA, TFIIA, TFIIB and acidic activation domains446
F148LInter-repeat strandActivation defective; diminished DNA binding275
T153IInter-repeat strandActivation defective; normal interaction with TATA, TFIIA, TFIIB, and acidic activation domains446
N159DS1′Diminished DNA binding; promoter-specific activation defects9
N159LS1′Activation defective; diminished DNA binding275
V161ES1′Diminished DNA binding387
V161AS1′Activation defective; diminished DNA binding9, 275
G174EH1′Physical interaction with Spt3123
E186AS2′-S3′ stirrupDiminished TFIIB binding; activation responsive276
E188AS2′-S3′ stirrupDiminished TFIIB binding; activation responsive276
L189AS2′-S3′ stirrupActivation competent; deficient in forming a TBP-TFIIB complex276
L189KS2′-S3′ stirrupActivation defective; deficient in forming a TBP-TFIIB complex248
P191SS2′-S3′ loopIntragenic suppressor of L205F; corrects altered TATA binding specificity10
I194F, V203T, L205V (TBPm3)S3′ and S4′Altered DNA binding specificity454
R196CS3′Diminished DNA binding387
V203KS4′Diminished DNA binding387
L205FS4′Altered TATA binding specificity10
F207YS4′-S5′ loopDiminished DNA binding387
K211LS5′Activation defective248
E236PH2′Activation defective; normal interaction with TATA, TFIIA, TFIIB, and acidic activation domains446
F237DImmediately follows H2′Activation defective; normal interaction with TATA; impaired interaction with TFIIA and TFIIB446
F237VDownstream of H2′Intragenic suppressor of G174E123
  • a The positions of the α-helices (H1, H2, H1′, and H2′) and β-sheets (S1 to S5 and S1′ and S5′) are indicated within the crystal structure of TBP shown in Fig. 2.