Deletion of an additional 63 bp caused an increase of about 60% more β-galactosidase activity. To confirm that the RNA polymerase binding regions are located within the sequences spanning up to the selleck products consensus -35 sequences, 3′ Selleckchem Olaparib end deletion constructs lacking sequences up to the -35 region for genes 14 and 19

(65 and 57 bp, respectively) were prepared and assessed for β-galactosidase activity. These deletions led to the complete loss of β-galactosidase activity (Figure 6A–B lane 11 and 6C–D lane 6). Figure 6 Deletion analysis of promoter regions of genes 14 and 19. β-galactosidase activity of extracts prepared from E. coli cultures of bacteria transformed with various deletion constructs was determined. Panels A and C have cartoons depicting deletion constructs and their orientations for genes 14 and 19, respectively. (Solid black boxes represent lacZ gene, and right and left arrowhead

lines show orientation of the promoter regions ligated in front of the lacZ coding sequence. Lengths INCB018424 of the promoter regions in base pairs are indicated on the left. Panels B and D contain the β-galactosidase activity analysis data. (β-galactosidase activity was expressed as percent activity relative to the activity observed for full length promoter segments.) Data are presented with SD values calculated from four independent experiments (P ≤ 0.001). Location of -10 and -35 regions To determine whether the consensus -35 and -10 represented true RNA polymerase binding site regions, constructs lacking either the predicted -35 or -10 alone or the regions spanning from -35 to -10 were generated, and the effect of the loss of these sequences on promoter activity was evaluated by measuring

β-galactosidase activity. Deletion of the predicted -35 regions alone or in combination with the -10 for both the genes resulted in decline of β-galactosidase activity to the background levels observed for negative controls. Deletion of the consensus -10 region alone for both the genes, however, resulted in no significant change to the promoter activity (Figure 7). The impact of the deletions of -35 and -10 are very similar for both genes’ promoters. Figure 7 Deletion analysis spanning the -35 and -10 regions of genes 14 and 19. β-galactosidase activity of extracts prepared from E. coli cultures of bacteria transformed HSP90 with -35 or -10 deletions or deletions spanning from -35 to 10 were determined. Panels A and C have cartoons depicting deletion constructs and their orientations for genes 14 and 19, respectively. Panels B and D contained the β-galactosidase activity analysis data. Data are presented with SD values calculated from four independent experiments (P ≤ 0.001). Discussion Differences in protein expression influenced by vertebrate and tick cell environment are now well documented for E. chaffeensis [18–20] and other tick-transmitted bacteria [12, 13, 15, 16]. We recently reported novel data describing differences in immune response in the murine host against E.