Table 1.

Expression of luciferase and β-galactosidase fromM. smegmatis and M. tuberculosis DNA fragments

PlasmidaCoordinates of mycobacterial fragmentbLuciferase (relative units)cβ-Galactosidase (relative units)c
−H2O2+H2O2Relative increment−H2O2+H2O2Relative increment
pSG10ter1.5 ± 0.61.9 ± 0.80.95 ± 0.04NTdNTNT
pSM128*NTNTNT1.2 ± 0.31.3 ± 0.31.11 ± 0.02
MS3137–821430 ± 1271,782 ± 2974.26 ± 0.76NTNTNT
MYS42/MYS65*222–82168 ± 877 ± 201.58 ± 0.06172 ± 15241 ± 5.21.32 ± 0.005
MYS44/MYS66*258–82151 ± 735 ± 0.10.70 ± 0.0915.4 ± 0.715.3 ± 1.50.99 ± 0.045
MYS48669–82117 ± 813 ± 50.78 ± 0.10NT NTNT
MT3157–766°106 ± 12308 ± 362.91 ± 0.01NT NTNT
MYT43264–766°81 ± 6297 ± 651.40 ± 0.30NT NTNT
MYT45296–766°137 ± 3392 ± 380.63 ± 0.12NT NTNT
  • a pSG10ter derivatives; pSM128 derivatives are indicated by an asterisk.

  • b Coordinates of the M. smegmatissequence are arbitrary, with coordinate 1 corresponding to position 245 in the sequence deposited in the GenBank database (accession no.AF196484 ). Coordinates of the M. tuberculosis sequence (°) are arbitrary, with coordinate 1 corresponding to position 2,156,900 in the reverse strand of the M. tuberculosis complete genome sequence (GenBank accession no. AL123456 ).

  • c Luciferase and β-galactosidase activities expressed by M. smegmatis mc2155 transformed with the plasmids were measured, as described in Materials and Methods, both in the absence of (−H2O2) and after (+H2O2) oxidative stress. Treatment with 0.125 mM and 0.5 mM H2O2 for 1 h was used in luciferase and β-galactosidase assays, respectively, depending on the different cell concentrations used in the two assays. Thex¯ values ± standard deviations of three to five independent clones tested are reported. The relative increment of activity upon oxidative stress is also indicated.

  • d NT, not tested.