caa a22 4500 467938687 CHVBK 20180406153005.0 cr unu---uuuuu 170328e20060601xx s 000 0 eng 10.1007/s10822-006-9071-1 doi (NATIONALLICENCE)springer-10.1007/s10822-006-9071-1 Mechanism of enhanced conversion of 1,2,3-trichloropropane by mutant haloalkane dehalogenase revealed by molecular modeling [Elektronische Daten] [Pavel Banáš, Michal Otyepka, Petr Jeřábek, Martin Petřek, Jiří Damborský] 1,2,3-Trichloropropane (TCP) is a highly toxic, recalcitrant byproduct of epichlorohydrin manufacture. Haloalkane dehalogenase (DhaA) from Rhodococcus sp. hydrolyses the carbon-halogen bond in various halogenated compounds including TCP, but with low efficiency (k cat/K m=36s-1M-1). A Cys176Tyr-DhaA mutant with a threefold higher catalytic efficiency for TCP dehalogenation has been previously obtained by error-prone PCR. We have used molecular simulations and quantum mechanical calculations to elucidate the molecular mechanisms involved in the improved catalysis of the mutant, and enantioselectivity of DhaA toward TCP. The Cys176Tyr mutation modifies the protein access and export routes. Substitution of the Cys residue by the bulkier Tyr narrows the upper tunnel, making the second tunnel "slot” the preferred route. TCP can adopt two major orientations in the DhaA enzyme, in one of which the halide-stabilizing residue Asn41 forms a hydrogen bond with the terminal halogen atom of the TCP molecule, while in the other it bonds with the central halogen atom. The differences in these binding patterns explain the preferential formation of the (R)- over the (S)-enantiomer of 2,3-dichloropropane-1-ol in the reaction catalyzed by the enzyme. Springer Science+Business Media, LLC, 2006 Directed evolution nationallicence Enantioselectivity nationallicence Molecular dynamics nationallicence Nucleophilic substitution nationallicence Quantum mechanics nationallicence Tunnels nationallicence Banáš Pavel Department of Physical Chemistry, Faculty of Science, Palacky University, tr. Svobody 26, 771 46, Olomouc, Czech Republic aut Otyepka Michal Department of Physical Chemistry, Faculty of Science, Palacky University, tr. Svobody 26, 771 46, Olomouc, Czech Republic aut Jeřábek Petr Loschmidt Laboratories, Faculty of Science, Masaryk University, Kamenice 5/A4, 625 00, Brno, Czech Republic aut Petřek Martin National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5/A4, 625 00, Brno, Czech Republic aut Damborský Jiří Loschmidt Laboratories, Faculty of Science, Masaryk University, Kamenice 5/A4, 625 00, Brno, Czech Republic aut Journal of Computer-Aided Molecular Design Kluwer Academic Publishers 20/6(2006-06-01), 375-383 0920-654X 20:6<375 2006 20 10822 https://doi.org/10.1007/s10822-006-9071-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10822-006-9071-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Banáš Pavel Department of Physical Chemistry, Faculty of Science, Palacky University, tr. Svobody 26, 771 46, Olomouc, Czech Republic aut NATIONALLICENCE 700 1- Otyepka Michal Department of Physical Chemistry, Faculty of Science, Palacky University, tr. Svobody 26, 771 46, Olomouc, Czech Republic aut NATIONALLICENCE 700 1- Jeřábek Petr Loschmidt Laboratories, Faculty of Science, Masaryk University, Kamenice 5/A4, 625 00, Brno, Czech Republic aut NATIONALLICENCE 700 1- Petřek Martin National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5/A4, 625 00, Brno, Czech Republic aut NATIONALLICENCE 700 1- Damborský Jiří Loschmidt Laboratories, Faculty of Science, Masaryk University, Kamenice 5/A4, 625 00, Brno, Czech Republic aut NATIONALLICENCE 773 0- Journal of Computer-Aided Molecular Design Kluwer Academic Publishers 20/6(2006-06-01), 375-383 0920-654X 20:6<375 2006 20 10822 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer