| X-RAY DIFFRACTION |
7.6 |
293 |
The crystal was grown by vapor diffusion from 4.5 mg/ml holo-NrdE in 50 mM HEPES (pH 7.6), 50 mM NaCl, 5 mM MgCl2, 2 mM TCEP, and 1% glycerol, supplemented with 5 mM ATP, 0.5 mM TTP, and 5 mM CDP. The protein solution was incubated for 10 minutes with freshly added nucleotides prior to being mixed in a 1:1 hanging drop with a precipitating solution of 6% PEG 3350, 1% w/v tryptone, and 50 mM HEPES at pH 6.9. Crystals were cryoprotected by soaking for 5-10 seconds in well solution mixed with 8% w/v sucrose, 2% w/v glucose, 8% v/v glycerol, 8% v/v ethylene glycol and supplemented with nucleotides, TCEP, and MgCl2 adjusted to the same concentrations used in the original protein solutions. |