4.1.2.52	crystallization of apo-HpcH, because divalent metal ion is lost during the purification process, resulting in preparation of the inactive apo form of the enzyme, crystals grown using the hanging-drop vapour diffusion method	
4.1.2.52	HpcH–Mg2+–oxamate crystals grown with the addition of 10 mM magnesium chloride and sodium oxamate (substrate analogue), elucidation of active site architecture	
4.1.2.52	in complex with substrate or products, hanging drop vapor diffusion method, using	
4.1.2.52	the active site of HpaI is formed by approx. 30 residues from adjacent dimers and consists of an approx. 15 A deep bell-shaped cleft with an approx. 12 A wide mouth. This broad entrance to the active site is predominantly lined with noncharged residues and a few positively charged residues