A. Sequence of the Ptar σ28-dependent promoter used in this study. Only the wt sequence is shown: single- or double- base changed promoter mutants were constructed from this parent. The native sequence of the tar promoter region is shown in capital letters; vector sequences are shown in lowercase; BglII and XbaI cloning sites are underlined; −35 and −10 regions, and the transcription start site are shown in bold.
B. Activity of σ28-dependent promoters in the presence of σ28 variants was determined by β-galactosidase assay from the ΔfliA and flgM strain, CAG57115, carrying the plasmids pSAKT28 and pQF50K. σ28expression was induced from pSAKT28 and derivatives (pBK201-pBK212), which has a p15A replication origin and fliA under control of the lac promoter. The reporter plasmid, pQF50K and derivatives (pBK601-pBK618) has a pMB1 replication origin and lacZ under control of the σ28-dependent tar promoter and promoter derivatives.