Structure of the complex of adenylate kinase from Escherichia coli with the inhibitor P1,P5-di(adenosine-5'-)pentaphosphate.

The enzyme adenylate kinase was isolated from Escherichia coli and crystallized together with a substrate-mimicking inhibitor. The crystal structure was solved using the multiple isomorphous replacement method at a resolution of 4.5 A (1 A = 0.1 nm). There are two enzyme-inhibitor complex molecules in the asymmetric unit, the relative positions of which are given. The resolution was extended to 2.3 A starting with the model of the homologous enzyme from yeast and using constrained-restrained and restrained refinements together with the known non-crystallographic symmetry. The final R-factor is 35.9%. The corresponding model is given as backbone tracing. The structure will be used for protein-engineering studies.