title: Identification of amino acid networks governing catalysis in the closed complex of class I terpene synthases.
abstract: Class I terpene synthases generate the structural core of bioactive terpenoids. Deciphering structure-function relationships in the reactive closed complex and targeted engineering is hampered by highly dynamic carbocation rearrangements during catalysis. Available crystal structures, however, represent the open, catalytically inactive form or harbor nonproductive substrate analogs. Here, we present a catalytically relevant, closed conformation of taxadiene synthase (TXS), the model class I terpene synthase, which simulates the initial catalytic time point. In silico modeling of subsequent catalytic steps allowed unprecedented insights into the dynamic reaction cascades and promiscuity mechanisms of class I terpene synthases. This generally applicable methodology enables the active-site localization of carbocations and demonstrates the presence of an active-site base motif and its dominating role during catalysis. It additionally allowed in silico-designed targeted protein engineering that unlocked the path to alternate monocyclic and bicyclic synthons representing the basis of a myriad of bioactive terpenoids.
authors: Division for Industrial Biocatalysis, Technische Universität München, 85748 Garching, Germany;
authors: Patrick
authors: http://orcid.org/0000-0003-1708-9630
authors: P
authors: Schrepfer
authors: Division for Industrial Biocatalysis, Technische Universität München, 85748 Garching, Germany;
authors: Alexander
authors: A
authors: Buettner
authors: Division for Industrial Biocatalysis, Technische Universität München, 85748 Garching, Germany;
authors: Christian
authors: C
authors: Goerner
authors: Division for Industrial Biocatalysis, Technische Universität München, 85748 Garching, Germany;
authors: Michael
authors: M
authors: Hertel
authors: Department of Theoretical Chemistry, Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr, Germany;
authors: Jeaphianne
authors: J
authors: van Rijn
authors: Chair of Bioinformatics and Computational Biology, Technische Universität München, 85748 Garching, Germany;
authors: Frank
authors: F
authors: Wallrapp
authors: Chair of Biochemistry, Technische Universität München, 85748 Garching, Germany;
authors: Wolfgang
authors: W
authors: Eisenreich
authors: Chair of Chemistry of Biogenic Resources, Technische Universität München, 94315 Straubing, Germany;
authors: Volker
authors: V
authors: Sieber
authors: Junior Research Group for Microbial Biotechnology, Ruhr-Universität Bochum, 44780 Bochum, Germany.
authors: Robert
authors: R
authors: Kourist
authors: Division for Industrial Biocatalysis, Technische Universität München, 85748 Garching, Germany; brueck@tum.de.
authors: Thomas
authors: T
authors: Brück
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000737:chemistry*; D020816:Amino Acid Motifs; D002384:Catalysis; D020134:Catalytic Domain; D008958:Models, Molecular; D020539:Sequence Analysis, Protein / Q000379:methods*
chemical_list: D019883:Alkyl and Aryl Transferases; C108877:terpene synthase
keywords: closed complex modeling; computational biology; protein engineering; terpene synthase catalysis; terpene synthases