Purification, crystallization and preliminary X-ray diffraction analysis of the effector protein PevD1 from Verticillium dahliae

The effector protein PevD1 from the pathogenic fungus Verticillium dahliae was purified and crystallized using the hanging-drop vapour-diffusion method. Native crystals appeared in a solution consisting of 4.0 M sodium formate. A native data set was collected at 1.9 angstrom resolution at 100 Kusing an in-house X-ray source. Because of the absence of useful methinione in the protein sequence, derivative crystals that contained iodine were obtained by soaking in 1.25 M potassium iodide, and a data set that contained anomalous signal was collected using the same X-ray facility at a wavelength of 1.54 angstrom. The single-wavelength anomalous dispersion method was used to successfully solve the structure based on the anomalous signal generated from iodine.