Table 3

Effect of eut mutations on expression of distal genes in operon

GenotypeaStrainMutation typeβ-Galactosidase expression from eut-38::Mud(Lac)bRatio of mutant to wild-type activity
ControlTT26869No mutation added277 ± 101.00
eutDTT26870In-frame deletion of eutD-coding sequence291 ± 171.05
eutQTDMNTT26877Truncated EutQ, no EutTDMN; EutE+316 ± 151.14
eutD eutQTT26871eutQ P32T missense271 ± 160.98
eutD eutMTT26873eutM G5R missense259 ± 140.94
eutD eutMTT26874eutM deletion, frameshift, termination263 ± 250.95
eutD eutMTT26875eutM frameshift, termination261 ± 120.94
eutD eutMTT26876eutM E84STOP nonsense, termination263 ± 110.95
eutD eutETT26872eutE E7K missense281 ± 231.01
  • a All strains had eut-38::Mud(Lac). The eut-38::Mud insertion fuses the lacZ gene to the eut operon at a point distal to all eut-coding sequences.

  • b Cells were grown on minimal glycerol ethanolamine medium. β-Galactosidase was assayed as described in Materials and Methods, and β-galactosidase expression is expressed in units described by Miller (26).