Tryptophan synthetase activities in W3110 and trpA34 strains containing AspRSs from D. radiodurans, C. trachomatis, and H. salinarum grown in the absence of tryptophan

aspS geneaAvg activity: (U/mg)b ± SDRelative activity (%)
W311015.74 ± 1.43100
DR23.59 ± 0.4923
CT2.54 ± 0.2116
HS5.98 ± 0.8438
  • a —, empty pCBS1 vector; DR1, D. radiodurans aspS1 in pCBS1; DR2, D. radiodurans aspS2 in pCBS1; CT, C. trachomatis aspS in pBAD-TOPO; HS, H. salinarum aspS in pBAD-TOPO plus tRNAAsn in pTECH.

  • b One activity unit is the amount of enzyme producing 0.1 μmol of Trp in 20 min at 37°C per mg of protein (18).