title: Structural basis for organohalide respiration.
abstract: Organohalide-respiring microorganisms can use a variety of persistent pollutants, including trichloroethene (TCE), as terminal electron acceptors. The final two-electron transfer step in organohalide respiration is catalyzed by reductive dehalogenases. Here we report the x-ray crystal structure of PceA, an archetypal dehalogenase from Sulfurospirillum multivorans, as well as structures of PceA in complex with TCE and product analogs. The active site harbors a deeply buried norpseudo-B12 cofactor within a nitroreductase fold, also found in a mammalian B12 chaperone. The structures of PceA reveal how a cobalamin supports a reductive haloelimination exploiting a conserved B12-binding scaffold capped by a highly variable substrate-capturing region.
authors.affiliation: Institut für Biologie, Strukturbiologie/Biochemie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Bommer
authors.affiliation: Institut für Mikrobiologie, Friedrich-Schiller-Universität Jena, Lehrstuhl für Angewandte und Ökologische Mikrobiologie, Philosophenweg 12, 07743 Jena, Germany.
authors.forename: Cindy
authors.initials: C
authors.lastname: Kunze
authors.affiliation: Institut für Biologie, Strukturbiologie/Biochemie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Fesseler
authors.affiliation: Institut für Mikrobiologie, Friedrich-Schiller-Universität Jena, Lehrstuhl für Angewandte und Ökologische Mikrobiologie, Philosophenweg 12, 07743 Jena, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Schubert
authors.affiliation: Institut für Mikrobiologie, Friedrich-Schiller-Universität Jena, Lehrstuhl für Angewandte und Ökologische Mikrobiologie, Philosophenweg 12, 07743 Jena, Germany. holger.dobbek@biologie.hu-berlin.de gabriele.diekert@uni-jena.de.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Diekert
authors.affiliation: Institut für Biologie, Strukturbiologie/Biochemie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany. holger.dobbek@biologie.hu-berlin.de gabriele.diekert@uni-jena.de.
authors.forename: Holger
authors.initials: H
authors.lastname: Dobbek
mesh_terms: D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D004579:Electron Transport; D020565:Epsilonproteobacteria / Q000201:enzymology*; D010088:Oxidoreductases / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D014241:Trichloroethylene / Q000737:chemistry*; D014805:Vitamin B 12 / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D014241:Trichloroethylene; D010088:Oxidoreductases; C112990:tetrachloroethene dehalogenase; D014805:Vitamin B 12