title: The crystal structure of Mycobacterium tuberculosis adenylate kinase in complex with two molecules of ADP and Mg2+ supports an associative mechanism for phosphoryl transfer.
abstract: The crystal structure of Mycobacterium tuberculosis adenylate kinase (MtAK) in complex with two ADP molecules and Mg2+ has been determined at 1.9 A resolution. Comparison with the solution structure of the enzyme, obtained in the absence of substrates, shows significant conformational changes of the LID and NMP-binding domains upon substrate binding. The ternary complex represents the state of the enzyme at the start of the backward reaction (ATP synthesis). The structure is consistent with a direct nucleophilic attack of a terminal oxygen from the acceptor ADP molecule on the beta-phosphate from the donor substrate, and both the geometry and the distribution of positive charge in the active site support the hypothesis of an associative mechanism for phosphoryl transfer.
authors: Unité de Biochimie Structurale, CNRS-URA 2185, Institut Pasteur, F-75724 Paris, France.
authors: Marco
authors: M
authors: Bellinzoni
authors: Ahmed
authors: A
authors: Haouz
authors: Martin
authors: M
authors: Graña
authors: Hélène
authors: H
authors: Munier-Lehmann
authors: William
authors: W
authors: Shepard
authors: Pedro M
authors: PM
authors: Alzari