Structural snapshots of OxyR reveal the peroxidatic mechanism of H 2 O 2 sensing.

Autor: Pedre B; Center for Structural Biology, Vlaams Instituut voor Biotechnologie-Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium., Young D; Center for Structural Biology, Vlaams Instituut voor Biotechnologie-Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium., Charlier D; Research Group of Microbiology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium., Mourenza Á; Department of Molecular Biology, Area of Microbiology, University of León, 24071 León, Spain., Rosado LA; Center for Structural Biology, Vlaams Instituut voor Biotechnologie-Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium., Marcos-Pascual L; Department of Molecular Biology, Area of Microbiology, University of León, 24071 León, Spain., Wahni K; Center for Structural Biology, Vlaams Instituut voor Biotechnologie-Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium., Martens E; Center for Structural Biology, Vlaams Instituut voor Biotechnologie-Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium., G de la Rubia A; Department of Molecular Biology, Area of Microbiology, University of León, 24071 León, Spain., Belousov VV; Department of Metabolism and Redox Biology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia.; Institute of Translational Medicine, Pirogov Russian National Research Medical University, Moscow 117997, Russia.; Institute for Cardiovascular Physiology, Georg August University Göttingen, 37073 Göttingen, Germany., Mateos LM; Department of Molecular Biology, Area of Microbiology, University of León, 24071 León, Spain; luis.mateos@unileon.es joris.messens@vib-vub.be., Messens J; Center for Structural Biology, Vlaams Instituut voor Biotechnologie-Vrije Universiteit Brussel, B-1050 Brussels, Belgium; luis.mateos@unileon.es joris.messens@vib-vub.be.; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2018 Dec 11; Vol. 115 (50), pp. E11623-E11632. Date of Electronic Publication: 2018 Nov 21.
DOI: 10.1073/pnas.1807954115
Abstrakt: Hydrogen peroxide (H 2 O 2 ) is a strong oxidant capable of oxidizing cysteinyl thiolates, yet only a few cysteine-containing proteins have exceptional reactivity toward H 2 O 2 One such example is the prokaryotic transcription factor OxyR, which controls the antioxidant response in bacteria, and which specifically and rapidly reduces H 2 O 2 In this study, we present crystallographic evidence for the H 2 O 2 -sensing mechanism and H 2 O 2 -dependent structural transition of Corynebacterium glutamicum OxyR by capturing the reduced and H 2 O 2 -bound structures of a serine mutant of the peroxidatic cysteine, and the full-length crystal structure of disulfide-bonded oxidized OxyR. In the H 2 O 2 -bound structure, we pinpoint the key residues for the peroxidatic reduction of H 2 O 2 , and relate this to mutational assays showing that the conserved active-site residues T107 and R278 are critical for effective H 2 O 2 reduction. Furthermore, we propose an allosteric mode of structural change, whereby a localized conformational change arising from H 2 O 2 -induced intramolecular disulfide formation drives a structural shift at the dimerization interface of OxyR, leading to overall changes in quaternary structure and an altered DNA-binding topology and affinity at the catalase promoter region. This study provides molecular insights into the overall OxyR transcription mechanism regulated by H 2 O 2 .
Competing Interests: The authors declare no conflict of interest.
(Copyright © 2018 the Author(s). Published by PNAS.)
Databáze: MEDLINE