An improved tetracycline-inducible expression vector for Staphylococcus aureus

The tetracycline-inducible expression vector pALC2073 allowed high level expression of the cloned sasG gene but repression by uninduced cells was leaky. The -10 box of the tetR promoter was mutated to the Bacillus subtitlis consensus, which resulted in complete repression of SasG protein expression. Anhydrotetracycline at 1.28 mu g ml(-1) gave the same high level of induction that was obtained with pALC2073sasG using 160 ng ml(-1) tetracycline, the highest concentration that could be used without inhibiting bacterial growth. This variant of pALC2073 thus offers almost complete repression when uninduced and high levels of expression when induced. (C) 2008 Elsevier Inc. All rights reserved.