TABLE 1.

Repression, activation, and DNA binding of variant SMK1 MSE sitesa

Substitution2468 1012 1416 18 C A A G T G T C A C A A A T T A G T G V N D N C R C A A W     D S Y G W C A Y W D W% Activity of:
Ndt80Sum1
Act.bBoundcRep.dBoundc
WT100100100100
A2CC87835425
A3CC3183310
A3TT551117563
A3GG7656188100
G4TT385031.4
G4CC3859588
G4AA18713450
T5AA578310.4
T5GG734020.4
T5CC62638067
G6AA3811130.1
G6CC202841
G6TT585620.4
T7CC26914387
T7AA118200188100
T7GG77100191
C8TT502440.05
C8GG284
C8AA16820.6
A9GG57294825
A9TT1913
A9CC201731
C10TT142923
C10GG1650
C10AA20233
A11TT181210520
A11CC1611
A11GG3113624
A12TT101818840
A12CC281
A12GG37144111
A13TT7731188125
A13CC232
A13GG4042340
T14GG1241662183
T14AA14887
T15GG58100188100
A16CC187125
G17TT9794
  • a The consensus sequences for Ndt80 (MSEN) (middle sequence at top of table) and Sum1 (MSES) (bottom sequence at top of table) activity and binding based upon the in vivo and in vitro analyses of mutations in the SMK1 MSE (top sequence) (WT) shown in this table. A base was included in the consensus if it gave a value of 50% or more in the in vitro or the in vivo assay or both. D: A, G or T; V: A, G, or C; N: A, G, C or T W: A or T; R: A or G; S: G or C; Y: C or T.

  • b The percent activity for transcriptional activation (Act.) by Ndt80 was calculated by comparing the activation of the mutant sites to activation of the wild-type site (defined as 100%) when Ndt80 is ectopically expressed. Ndt80 activated the wild-type SMK1 MSE reporter 6.2 fold (18.7 β-galactosidase units) over the reporter lacking the site (3 β-galactosidase units) when NDT80 expression was induced in a sum1 mutant strain.

  • c The percent binding (Bound) was calculated by measuring the ability of Sum1 or Ndt80 to bind to each mutant sequence compared to binding to the wild-type sequence. Several concentrations of protein were tested with each mutant site.

  • d The percent activity for repression (Rep.) by Sum1 was calculated by measuring reporter gene expression and comparing the repression conferred by each mutant site to the repression of the wild-type site (defined as 100%). The wild-type site represses the reporter 46-fold (0.4 β-galactosidase units) compared to a reporter lacking the site (18.3 β-galactosidase units) in a wild type SUM1 strain.