title: Preliminary X-ray investigation of enzyme substrate complexes of horse muscle phosphoglycerate kinase.
abstract: Crystals of horse muscle 3-phosphoglycerate kinase have been grown in the presence of a wide variety of substrates using either potassium tartrate or polyethylene glycol as a precipitant. In those grown from polyethylene glycol, two related crystal forms have been obtained by varying the nature of the substrates present in the crystallization medium. In order to obtain one of these forms, form B, the presence of the substrate 3-phosphoglycerate appears to be essential. The two crystal forms are not interconvertible by simple diffusion experiments and the crystals grown in the absence of 3-phosphoglycerate are destroyed by its addition. The properties of crystal form B would be consistent with it representing a "hinge closed" form for this enzyme.
mesh_terms: D000255:Adenosine Triphosphate; D000818:Animals; D001665:Binding Sites; D003461:Crystallography; D005988:Glyceric Acids / Q000378:metabolism; D006736:Horses; D008274:Magnesium; D009132:Muscles / Q000201:enzymology*; D010735:Phosphoglycerate Kinase / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D005988:Glyceric Acids; C005156:3-phosphoglycerate; D000255:Adenosine Triphosphate; D010735:Phosphoglycerate Kinase; D008274:Magnesium