title: A Rieske-Type Oxygenase of Pseudomonas sp. BIOMIG1 Converts Benzalkonium Chlorides to Benzyldimethyl Amine.
abstract: Recently, an array of eight genes involved in the biotransformation of benzalkonium chlorides (BACs)-an active ingredient of many disinfectants-to benzyldimethyl amine (BDMA) was identified in the genome of Pseudomonas sp. BIOMIG1, which is a bacterium present in various environments and mineralizes BACs. In this study, we showed that heterologous expression of an oxygenase gene (oxyBAC) present in this gene array in E. coli resulted in formation of BDMA from BACs at a rate of 14 μM h-1. oxyBAC is phylogenetically classified as a Rieske-type oxygenase (RO) and belongs to a group which catalyzes the cleavage of C-N+bond between either methyl or alkyl ester and a quaternary nitrogen (N) of natural quaternary ammonium compounds such as stachydrine, carnitine, and trimethylglycine. Insertion of two glycines into the Rieske domain and substitution of tyrosine with leucine in the mononuclear iron center differentiate oxyBAC from other ROs that cleave C-N+, and presumably facilitate the cleavage of saturated alkyl chain from quaternary N via N-dealkylation reaction. In addition, unlike other ROs, oxyBAC did not require a specific reductase to function. Our results demonstrate that oxyBAC represents a new member of RO associated with BAC degradation, and have applications for controlling the fate of BACs in the environment.
authors: Institute of Environmental Sciences and ‡Center for Life Sciences and Technologies, Bogazici University , Bebek 34342 Istanbul, Turkey.|School of Civil and Environmental Engineering and ∥School of Biology, Georgia Institute of Technology , Atlanta, Georgia 30332-0512, United States.
authors: Emine
authors: E
authors: Ertekin
authors: Institute of Environmental Sciences and ‡Center for Life Sciences and Technologies, Bogazici University , Bebek 34342 Istanbul, Turkey.|School of Civil and Environmental Engineering and ∥School of Biology, Georgia Institute of Technology , Atlanta, Georgia 30332-0512, United States.
authors: Konstantinos T
authors: KT
authors: Konstantinidis
authors: Institute of Environmental Sciences and ‡Center for Life Sciences and Technologies, Bogazici University , Bebek 34342 Istanbul, Turkey.|School of Civil and Environmental Engineering and ∥School of Biology, Georgia Institute of Technology , Atlanta, Georgia 30332-0512, United States.
authors: Ulas
authors: U
authors: Tezel
mesh_terms: D000588:Amines / Q000378:metabolism; D001548:Benzalkonium Compounds; D004926:Escherichia coli / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism; D011549:Pseudomonas / Q000378:metabolism*
chemical_list: D000588:Amines; D001548:Benzalkonium Compounds; D010105:Oxygenases