2013
The Effect of a Unique Halide-Stabilising Residue on the Catalytic Properties of Haloalkane Dehalogenase DatA from Agrobacterium tumefaciens C58
HASAN, Khomaini; Artur Wiktor GORA; Jan BREZOVSKÝ; Radka CHALOUPKOVÁ; Hana MOSKALÍKOVÁ et. al.Basic information
Original name
The Effect of a Unique Halide-Stabilising Residue on the Catalytic Properties of Haloalkane Dehalogenase DatA from Agrobacterium tumefaciens C58
Authors
HASAN, Khomaini (360 Indonesia, belonging to the institution); Artur Wiktor GORA (616 Poland, belonging to the institution); Jan BREZOVSKÝ (203 Czech Republic, belonging to the institution); Radka CHALOUPKOVÁ (203 Czech Republic, belonging to the institution); Hana MOSKALÍKOVÁ (203 Czech Republic, belonging to the institution); Andrea FOŘTOVÁ (203 Czech Republic, belonging to the institution); Yuji NAGATA (392 Japan); Jiří DAMBORSKÝ (203 Czech Republic, guarantor, belonging to the institution) and Zbyněk PROKOP (203 Czech Republic, belonging to the institution)
Edition
FEBS Journal, Blackwell, 2013, 1742-464X
Other information
Language
English
Type of outcome
Article in a journal
Field of Study
10600 1.6 Biological sciences
Country of publisher
United States of America
Confidentiality degree
is not subject to a state or trade secret
Impact factor
Impact factor: 3.986
RIV identification code
RIV/00216224:14310/13:00065822
Organization unit
Faculty of Science
UT WoS
000320557100016
Keywords in English
Haloalkane Dehalogenase
Changed: 29/4/2014 14:23, Ing. Zdeňka Rašková
Abstract
In the original language
Haloalkane dehalogenases catalyse the hydrolysis of carbon-halogen bonds in various chlorinated, brominated and iodinated compounds. These enzymes have a conserved pair of halide-stabilising residues that are important in substrate binding and stabilisation of the transition state and the halide ion product via hydrogen bonding. In all previously known haloalkane dehalogenase, these residues are either a pair of tryptophans or a tryptophan-asparagine pair. The newly isolated haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58 possesses a unique halide-stabilising tyrosine residue, Y109, in place of the conventional tryptophan. A variant of DatA with the Y109W mutation was created and the effects of this mutation on the enzyme’s structure and catalytic properties were studied using spectroscopy and pre-steady-state kinetic experiments. Quantum mechanical and molecular dynamics calculations were used to obtain a detailed analysis of the hydrogen bonding patterns within the active sites of the wild-type and the mutant, and of the stabilisation of the ligands as the reaction proceeds. Fluorescence quenching experiments suggested that replacing the tyrosine with tryptophan improves halide binding 3.7-fold, presumably due to the introduction of an additional hydrogen bond. Kinetic analysis revealed that the mutation affected the enzyme’s substrate specificity and reduced its K0.5 for selected halogenated substrates by a factor of 2-4, without impacting the rate-determining hydrolytic step. We conclude that DatA is the first natural haloalkane dehalogenase that stabilises its substrate in the active site using only a single hydrogen bond, which is a new paradigm in catalysis by this enzyme family.
Links
ED0001/01/01, research and development project |
| ||
GAP207/12/0775, research and development project |
| ||
GAP503/12/0572, research and development project |
| ||
IAA401630901, research and development project |
|