4.2.3.12	-	
4.2.3.12	ePTPS is crystallized using the hanging-drop vapour-diffusion method. Hexagonal- and rectangular shaped crystals are obtained. Diffraction data are collected from the hexagonal and rectangular crystals to 3.0 and 2.3 A resolution, respectively. The hexagonal plate-shaped crystals belonged to space group P321, with unit-cell parameters a = b = 112.59, c = 68.82 A , and contained two molecules in the asymmetric unit. The rectangular crystals belonged to space group I222, with unit-cell parameters a = 112.76, b = 117.66, c = 153.57 A, and contain six molecules in the asymmetric unit	
4.2.3.12	overexpressed as native and selenomethionine-substituted protein and the purified protein is crystallized by the oil-microbatch method at 22°C. 2.1 A resolution from the native crystal using synchrotron radiation at 100 K. The crystal belongs to the orthorhombic space group P212121, with unit-cell parameters a = 35.83, b = 95.71, c = 05.65 A. The selenomethionine-substituted crystal is isomorphous to the native crystal and diffracts X-rays to 2.9 A	
4.2.3.12	X-ray crystal structure of the PTPS homolog from Streptomyces coelicolor, SCO 6650, is solved at 1.5 A resolution. SCO 6650 forms a hexameric T-fold that closely resembles other PTPS proteins. The biological activity of SCO 6650 is unknown, but it lacks both a required active-site zinc metal ion and the essential catalytic triad and does not catalyze the PTPS reaction. SCO 6650 maintains active-site residues consistent with binding a pterin-like substrate	
4.2.3.12	X-ray crystallography	
4.2.3.12	X-ray crystallography, sitting drop vapor diffusion