title: Structural basis for catalytically restrictive dynamics of a high-energy enzyme state.
abstract: An emerging paradigm in enzymology is that transient high-energy structural states play crucial roles in enzymatic reaction cycles. Generally, these high-energy or 'invisible' states cannot be studied directly at atomic resolution using existing structural and spectroscopic techniques owing to their low populations or short residence times. Here we report the direct NMR-based detection of the molecular topology and conformational dynamics of a catalytically indispensable high-energy state of an adenylate kinase variant. On the basis of matching energy barriers for conformational dynamics and catalytic turnover, it was found that the enzyme's catalytic activity is governed by its dynamic interconversion between the high-energy state and a ground state structure that was determined by X-ray crystallography. Our results show that it is possible to rationally tune enzymes' conformational dynamics and hence their catalytic power--a key aspect in rational design of enzymes catalysing novel reactions.
authors.affiliation: Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå 90187, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Kovermann
authors.affiliation: Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå 90187, Sweden.
authors.forename: Jörgen
authors.initials: J
authors.lastname: Ådén
authors.affiliation: Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå 90187, Sweden.
authors.forename: Christin
authors.initials: C
authors.lastname: Grundström
authors.affiliation: Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå 90187, Sweden.
authors.forename: A Elisabeth
authors.initials: AE
authors.lastname: Sauer-Eriksson
authors.affiliation: Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå 90187, Sweden.
authors.forename: Uwe H
authors.initials: UH
authors.lastname: Sauer
authors.affiliation: Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå 90187, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Wolf-Watz
mesh_terms: D000244:Adenosine Diphosphate / Q000096:biosynthesis*; D000263:Adenylate Kinase / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002384:Catalysis; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D056004:Molecular Dynamics Simulation; D016297:Mutagenesis, Site-Directed; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D000244:Adenosine Diphosphate; D000263:Adenylate Kinase