ausblenden:
Schlagwörter:
adenylate kinase; bisubstrate inhibitor; Crystallization; Dictyostelium-discoideum; Ump/cmp-kinase; x-ray analysis
Zusammenfassung:
UMP/ICMP-kinase (UK) from the slime mold Dictyostelium discoideum has been purified to high homogeneity and co-crystallized with the bisubstrate inhibitor P1-(adenosine 5′)-P5-(uridine 5′)-pentaphosphate (UP5A). UP5A binds to UK with a dissociation constant (K d ) of 3 ± 0.5 nM at 25°C and pH 7.5. This is some 50-fold tighter than the binding of P1,P5-(diadenosine 5′)-pentaphosphate (AP5A, K d = 160 ± 15 nM). AP5A is a bisubstrate inhibitor that is specific for adenylate kinase. The crystals have the symmetry of the tetragonal space group P41212 or its enantiomorph P43212. The unit cell dimensions are math formula. The crystals diffract to a Bragg spacing of 2.1 Å.