3.1.11.5 | purified recombinant enzyme complex RecBCD bound with a DNA substrate (a 350 kDa complex) or ATP analogue ADPNP, mixing of 0.0015 ml of 5 mg/ml protein, and a 1.75fold excess of DNA, 2 mM ADPNP, and 4 mM MgCl2, in 20 mM Tris-HCl, pH 7.5, 50 mM NaCl, and 1 mM TCEP, with 0.03 ml of 0.1% detergent n-dodecyl beta-D-maltoside on ice, incubation at 4°C overnight, X-ray diffraction structure determination and analysis at 3.8 A resolution, molecular replacement and modelling using the crystal structure of RecBCD in complex with an extended DNA fork (PDB ID 3K70) as a template |