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Journal articles
Structural insights into the metabolism of 2-chlorodibenzofuran by an evolved biphenyl dioxygenase.
Abstract : The biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE(LB400)) is a Rieske-type oxygenase that catalyzes the stereospecific oxygenation of many heterocyclic aromatics including dibenzofuran. In a previous work, we evolved BphAE(LB400) and obtained BphAE(RR41). This variant metabolizes dibenzofuran and 2-chlorodibenzofuran more efficiently than BphAE(LB400). However, the regiospecificity of BphAE(RR41) toward these substrates differs. Dibenzofuran is metabolized principally through a lateral dioxygenation whereas 2-chlorodibenzofuran is metabolized principally through an angular dioxygenation. In order to explain this difference, we examined the crystal structures of both substrate-bound forms of BphAE(RR41) obtained under anaerobic conditions. This structure analysis, in combination with biochemical data for a Ser283Gly mutant provided evidences that the substrate is compelled to move after oxygen-binding in BphAE(RR41):dibenzofuran. In BphAE(RR41):2-chlorodibenzofuran, the chlorine atom is close to the side chain of Ser283. This contact is missing in the BphAE(RR41):dibenzofuran, and strong enough in the BphAE(RR41):2-chlorodibenzofuran to help prevent substrate movement during the catalytic reaction.
https://hal-riip.archives-ouvertes.fr/pasteur-00818384
Contributor : Charles M. Dozois Connect in order to contact the contributor
Submitted on : Friday, April 26, 2013 - 5:08:18 PM
Last modification on : Monday, October 8, 2018 - 5:44:04 PM
Contributor : Charles M. Dozois Connect in order to contact the contributor
Submitted on : Friday, April 26, 2013 - 5:08:18 PM
Last modification on : Monday, October 8, 2018 - 5:44:04 PM