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, ...

Artificial transcription elongation compexes are assembled in vitro using synthetic deoxy-oligonucleotides (representing template and non template DNA strands), radiolabelled RNA (representing nascent transcript) and purified RNA polymerase. After high salt wash the incorrect NTP is added and reaction is allowed to proceed for the various amounts of time. Reaction is stopped by addition of formamide-containing loading solution and the products are resolved on high-percentage denaturing polyacryamide ...

S.pneumoniae D39 cells (wild type and delta greA) were grown in C+Y medium and cells were harvested for total RNA isolation at mid-exponential growth (OD600nm 0.3 for wt, 0.25 for delta greA). Total RNA was isolated as described before (Kloosterman et al 2006). The total RNA samples were examined by capillary electrophoresis. dephosphorylated with antarctic phosphatase followed by treatment with polynucleotide kinase (PNK). Afterwards, samples were poly(A)-tailed using poly(A) polymerase. Then a ...

1. Preparation of B. subtilis cultures

Inoculate cells from -80°C stocks in 10 ml time-lapse microscopy (TLM) medium (62 mM K2HPO4 , 44mM KH2PO4, 15 mM (NH4)2SO4, 6.5 mM sodium citrate, 0.8 mM MgSO4, 0.02 % casamino acids, 27.8 mM glucose, 0.1 mM L-tryptophan, the pH was set to 7 using a KOH solution) supplemented with antibiotics, if necessary. Grow the cells overnight in a shake flask (30°C, 225 rpm). The following morning, dilute the cells 1:10 in pre-warmed chemically defined medium (CDM) (62 ...