Table 2.

Growth phenotypes of dadRAX mutants and effects of amino acids on dadA promoter activity

Amino acidAmino acid growth phenotype (d form)adadA promoter activityb
PAO1ΔdadRΔdadAΔdadXdl
Ala++/−+12.128.9
Val++/−+1.715.7
Ser++/−+26.2
Thr++/−+4.15.7
Phe++/−+0.70.8
His++/−+10.8
Arg++++21.5
Lys++++0.95.1
Asn++++0.71.4
Gln++++10.7
Glu++++11
Pro++++1.81.9
Asp0.40.5
Cys1.22.7
Leu0.91.8
Met1.41.4
Trp1.48.4
Tyr0.81.3
IleNDNDNDNDND1.2
GlyNANANANANA3
  • a +, growth; +/−, poor growth,; −, no growth; NA, not available; ND, not determined. Growth was monitored at 37°C for 48 h in glucose minimal medium, with the indicated amino acid as the sole nitrogen source.

  • b Cells were grown in minimal medium P with 20 mM glucose and 5 mM d-amino acids (d, d-amino acids; l, l-amino acids). Activity of the dadA promoter fused with lacZ in pZY6 (22) was measured. Values indicate fold changes in β-galactosidase activities in comparison to the level in Glu-grown cells. Each value represents the average from two measurements, with standard errors below 5%.