Fig. 2.

Quantification of MutL protein level in different strains. (A) Position of the miniTn10 insertion within the amiB-mutL–miaA-hfq-hflX superoperon. pmutL and pmutLHS, mutL gene promoters; miniTn10 (hatched box), transposon; ptetA and ptetR, Tn10 tetracycline-inducible promoters. (B) Cellular level of MutL protein determined by immunoblotting. Values represent fold difference over the control calculated from the average of three independent experiments. wt, wild-type strain; mutL_down, mutant strain with miniTn10 insertion in the amiB gene; pMutL and pMutS, wild-type strains carrying plasmids that overexpress MutL or MutS proteins, respectively; pVector, wild-type strain carrying control plasmid; tc, tetracycline; nd, not detected.