Constitutive MAL61 expression suppresses the defective mal13 MAL activator but not mal33 of strain YPH500a

MAL activator allelesPlasmidMaltase activityb
G/LG/L + maltose
mal13 mal33 [MAL63]Vector401,177
mal13 mal33 [MAL63]pADH1-MAL61/HA371,522
mal13 mal33Vector50129
mal13 mal33pADH1-MAL61/HA161,180
mal13Δ mal33Vector3038
mal13Δ mal33pADH1-MAL61/HA5697
mal13 mal33ΔVector3053
mal13 mal33ΔpADH1-MAL61/HA421,240
mal13Δ mal33ΔVector3832
mal13Δ mal33ΔpADH1-MAL61/HA12134
  • a Strain YPH500 and isogenic disruptions of defective mal13 (CMY1071), mal33 (CMY1072), and both mal13 and mal33 (CMY1073) were transformed with plasmid pADH1-MAL61/HA or the vector control pUN30. As a control, YPH500 was also transformed with the functional MAL-activator MAL63 carried in vector pUN70 (lines 1 and 2). Cells were grown in selective uninduced (3% glycerol and 2% lactate) and induced (3% glycerol, 2% lactate, and 2% maltose) media to mid-log phase. Maltase activity was assayed as described in Materials and Methods.

  • b Expressed as nanomoles of PNPG hydrolyzed per milligram of total protein per minute.