Fig. 5.

Functionalities of HicB domains. a DNA fragment coding for NH2 domain (COG1598) and COOH domain (RHH1) of HicB were amplified by PCR and introduced into pUT18, pUT18C, pKT25 and pKNT25 vectors allowing fusion of these domains with T25 and T18 fragments of B. pertussis adenylate cyclase (All the combinations are shown in Fig. S6). Plasmids were introduced in E. coli strain BTH101, and the cells were grown in LB medium containing 1 mM IPTG and β-galactosidase activity was assayed. b RHH1 domain binds operator sequence. Increasing amounts (0 to 5 μM) of RHH1 domain fused to 6 His were incubated with the promoter region of hicAB operon (223 bp PCR fragment used in Fig. 2). Then a 5% PAGE in Tris acetate buffer pH 7.5 was performed to resolve the protein DNA complexes (indicated by an arrow).