​softberry.​com) [26]. Sequence analysis revealed the presence of a potential binding site for the DNA-binding/bending protein IHF. This sequence was located at positions -64 to -44, relative to the start of phtD transcription,

and showed similarity to the consensus IHF binding site proposed by Kur et al. [27] (Figure 3A). Figure 3 Bioinformatic analysis of the sequence upstream of the phtD operon, and Supershift and Shift-western experiments to analyze the DNABII-family proteins binding activity to the P phtD fragment. (A) Bioinformatic analyses. This panel schematizes the intergenic region between phtC and phtD where the IHF BAY 11-7082 clinical trial binding site position is represented with a yellow barrel. The alignment of the phtD IHF binding site with the consensus IHF binding site proposed by Kur et al [27] is also shown. The sequence identified as the putative IHF binding site in the phtD promoter is shown in bold red letters. W: A or T; R: A or

G; N, any base. (B) Supershift assays. Analyses were conducted using increasing concentrations of anti DNAB-II family https://www.selleckchem.com/products/AZD8931.html proteins antibody. Supershift signals were observed when antibody was added to the reaction mixture. The specific DNA-protein complex is indicated by a solid arrow. Supershift bands are indicated by solid arrowheads. (C) Shift-western experiment. Gel shift assays with the P phtD probe were performed as described in the Methods, followed by transfer of proteins onto nitrocellulose membranes, which were probed with antibody to DNA-binding proteins of DNAB-II family. To identify the signal, the images were analyzed using Quantity-one software (BIO-RAD) following the manufacturer’s

instructions. Panel I depicts a standard gel mobility assay with radiolabeled P phtD probe. Lane 1, free probe; lane 2, DNA-protein complex. Panel II: Immunoblot using polyclonal antibody. Lanes correspond to those of Panel I. The arrow indicates the position of the gel shift band. Members Cepharanthine of the DNABII family (HU or IHF) interact with the P phtD fragment IHF is a learn more member of the DNABII DNA-binding protein family, which includes HU (a histone-like protein from E. coli strain U93) and IHF proteins [28]. The IHF protein has been reported to regulate the expression of several genes, some of which are involved in virulence factor synthesis [29, 30]. To assess whether IHF might interact with the phtD promoter region, and whether it was involved in the formation of the complex observed in gel mobility shift assays, we performed supershift assays. Supershift assays were carried out using a polyclonal antibody directed against DNA-binding proteins of the DNABII family (IHF and HU proteins).