DosR binds to DNA upstream of the acr coding sequence. SDS-PAGE analysis of DosR expression in E. coli. The dosR coding sequence was cloned into a pET expression vector, and expression was induced by IPTG. Lanes (1–3) full length: 1, uninduced; 2, induced for 2 h; 3, induced for 5 h; lanes (4–5) amino acids 1–134: 4, uninduced; 5, induced for 5 h; lanes (6–7) amino acids 144–217: 6, uninduced; 7, induced for 5 h. Arrows indicate the position at which DosR is expected to migrate.Electrophoretic mobility shift assay (EMSA) of E. coli extracts with full-length, N-terminal and C-terminal portions of DosR and radiolabelled acr promoter DNA. Lanes: 1, no extract; 2, amino acids 1–217 (full length); 3, amino acids 1–134; 4, amino acids 144–217.