coli was click here found to consistently produce β-galactosidase in the pBLUE TOPO vector in preliminary experiments, and was used as a positive control. Because the arabinose operator was not included in the positive control, the addition of arabinose was not required to produce β-galactosidase. A 49 bp segment of the jamaicamide jamG gene was used as a negative control. [Note: the pBLUE vector contains a
cryptic promoter that is reported to possibly limit the efficacy of assaying other promoter fragments in a prokaryotic host (Invitrogen). However, a series of preliminary assays indicated significant and repeatable differences in promoter activity between possible promoter regions, and baseline activity in the negative control was sufficiently low as to not conflict with the assay results. The BPROM prediction software was used to verify that the vector constructs did not introduce any artificial promoters]. Those regions found to have promoter activity were assayed again with AZD4547 additional dilution (10 fold) to quantify promoter strength, expressed as specific activity (nmol ONPG hydrolyzed min-1 mg soluble protein-1). Isolation of possible transcription
factors from a pulldown assay Protein pulldown experiments were based on methods similar to [53]. A DNA probe that extended from 1000 bp upstream of jamA to 20 bp into the jamA gene was amplified by PCR from the jamaicamide fosmid described above using the primers upjamA 1000 biotin (biotinylated at the 5′ end; Invitrogen) Caspase inhibitor reviewCaspases apoptosis and upjamA 20 – 0 R (Additional file 1: Table S1). The PCR product was purified (MinElute PCR Purification Kit, Palbociclib cost Qiagen) and 10 pmol of the biotinylated DNA were incubated with 1 mg of magnetic M-270 streptavidin Dynabeads (Invitrogen), according to the manufacturer’s instructions. L. majuscula JHB tissue was obtained from pan cultures that had been growing for 1-2 months. Approximately 2-3 ml of culture was measured by displacement in sterile, chilled binding buffer
[10 mM Tris-HCl (pH 7.5), 1 mM EDTA, 1 mM DTT, 150 mM NaCl, and 5% (w/v) glycerol]. The binding buffer was also treated with a broad range protease inhibitor (Complete, EDTA free; Roche). The tissue was sonicated and kept on ice using a probe sonicator with six 10-s pulses, and insoluble material was pelleted at 13,200 RPM for 10 minutes. The soluble protein fraction (750 μl) was added to each mg of DNA coated beads. One μg of Poly DI-DC was also added to inhibit non-specific binding of protein to the DNA. Magnetic beads that were not treated with biotinylated DNA were incubated with JHB soluble protein as a negative control. The beads and soluble protein were incubated for 1 h using an end-over-end rotator at 4°C. The beads were subsequently washed twice using 200 μl of binding buffer containing 100 μl sheared salmon sperm DNA (Invitrogen; 5 mg ml-1), three times with binding buffer, and eluted with 50 μl of binding buffer containing 1.0 M NaCl.