Assays

Cells were grown to mid-exponential phase (OD600nm ~0.2) in GM17 medium at 37°C (with 0.15 mM ZnSO4 where relevant) and 84 ml of culture was mixed by inverting with 8.4 ml of fixing solution (50 mM Tris pH 8.0, 100 mM NaCl, 0.5 mM EGTA, 1 mM EDTA, 30% (v/v) formaldehyde) and incubated at room temperature for 30 min. Cells were disrupted and crosslinked DNA was sheared by sonication. Antibodies coupled to magnetic beads were used to pull down cross-linked complexes. DNA was purified, amplified, ...