Association of MrpC and/or MrpC2 and FruA with the fmgE promoter region during development. ChIP analysis of M. xanthus at 18 h into development. Cells were treated with formaldehyde and lysed. Cross-linked chromatin was immunoprecipitated with antibodies. DNA was amplified with primers for the fmgE promoter region (positions −100 to +50 relative to the start site of transcription) or for the rpoC coding region (positions +1780 to +1905 relative to the predicted translation start) as a control. A 2-fold dilution series of input DNA purified from 0.025, 0.0125, 0.00625, or 0.003125% of the total cellular extract prior to immunoprecipitation was used as a template in parallel PCRs to show that the PCR conditions allow detection of differences in DNA concentration for each primer set. (A) Wild-type strain DK1622 with affinity-purified IgG antibodies against MrpC (α-MrpC) or, as a control, with total IgG (IgG) from nonimmunized rabbits. (B) Wild-type strain DK1622 with antiserum against FruA (α-FruA) or, as a control, preimmune antiserum (Pre). (C) fruA mutant strain DK5285 with antibodies as shown in panel A.