Stepwise enhancement of catalytic performance of haloalkane dehalogenase LinB towards β-hexachlorocyclohexane.
Two haloalkane dehalogenases, LinBUT and LinBMI, each with 296 amino acid residues, exhibit only seven amino acid residue differences between them, but LinBMI's catalytic performance towards β-hexachlorocyclohexane (β-HCH) is considerably higher than LinBUT's. To elucidate the molecular basis governing this difference, intermediate mutants between LinBUT and LinBMI were constructed and kinetically characterized. The activities of LinBUT-based mutants gradually increased by cumulative mutations into LinBUT, and the effects of the individual amino acid substitutions depended on combination with other mutations. These results indicated that LinBUT's β-HCH degradation activity can be enhanced in a stepwise manner by the accumulation of point mutations.
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan ; The United Graduate School of Agricultural Science, Gifu University 1-1 Yanagido, Gifu 501-1193, Japan.
Ryota
R
Moriuchi
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Hiroki
H
Tanaka
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Yuki
Y
Nikawadori
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Mayuko
M
Ishitsuka
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan ; Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, 2-2 Wakamatsu-cho, Shinjuku, Tokyo 162-8480, Japan.
Michihiro
M
Ito
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Yoshiyuki
Y
Ohtsubo
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Masataka
M
Tsuda
Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, Brno, 625 00, Czech Republic.
Jiri
J
Damborsky
Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, Brno, 625 00, Czech Republic.
Zbynek
Z
Prokop
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Yuji
Y
Nagata
Biodegradation; Haloalkane dehalogenase; Protein evolution; Xenobiotics; β-Hexachlorocyclohexane