3.5.4.13	apoenzyme in complex with dCTP and with dUTP	
3.5.4.13	in complex with dTTP, hanging drop vapor diffusion method, using 200 mM lithium citrate and 20% (w/v) polyethylene glycol 4000	
3.5.4.13	mutant E138A bound to dTTP and mutant H121A bound to dCTP, hanging drop vapour diffusion method, 3.7 mg/ml E138A or 5.1 mg/ml H121A in 20 mM magnesium chloride, 50 mM HEPES, pH 6.8, and 5 mM nucleotide, mixing of 0.002 ml of protein solution with an equal volume of reservoir solution containing 34% PEG 400, 0.2 mM MgCl2, and 0.1 m HEPES, pH 7.5, equilibration against 1 ml of mother liquor, room temperature, 1 week, X-ray diffraction structure determination and analysis at 2.6-2.7 A resolution	
3.5.4.13	recombinant mutant E138D in complex with dUTP, hanging drop vapour diffusion method, 0.002 ml of 2 mg/ml protein in solution with 5 mM dUTP and 20 mM MgSO4 is mixed with 0.002 ml reservoir solution containing 27.5% PEG 400, 50 mM MgSO4 and 0.1 M HEPES, pH 7.5, equilibration against 0.5 ml of reservoir solution, room temeprature, crystal X-ray diffraction structure determination and analysis at 2.1 A resolution	
3.5.4.13	wild-type and mutant E138A, in complex with Mg2+ and dUTP, and dCTP