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Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy

Quinol-dependent nitric oxide reductases (qNORs) are membrane-integrated, iron-containing enzymes of the denitrification pathway, which catalyze the reduction of nitric oxide (NO) to the major ozone destroying gas nitrous oxide (N(2)O). Cryo–electron microscopy structures of active qNOR from Alcalig...

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Autores principales: Gopalasingam, Chai C., Johnson, Rachel M., Chiduza, George N., Tosha, Takehiko, Yamamoto, Masaki, Shiro, Yoshitsugu, Antonyuk, Svetlana V., Muench, Stephen P., Hasnain, S. Samar
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6713497/
https://www.ncbi.nlm.nih.gov/pubmed/31489376
http://dx.doi.org/10.1126/sciadv.aax1803
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author Gopalasingam, Chai C.
Johnson, Rachel M.
Chiduza, George N.
Tosha, Takehiko
Yamamoto, Masaki
Shiro, Yoshitsugu
Antonyuk, Svetlana V.
Muench, Stephen P.
Hasnain, S. Samar
author_facet Gopalasingam, Chai C.
Johnson, Rachel M.
Chiduza, George N.
Tosha, Takehiko
Yamamoto, Masaki
Shiro, Yoshitsugu
Antonyuk, Svetlana V.
Muench, Stephen P.
Hasnain, S. Samar
author_sort Gopalasingam, Chai C.
collection PubMed
description Quinol-dependent nitric oxide reductases (qNORs) are membrane-integrated, iron-containing enzymes of the denitrification pathway, which catalyze the reduction of nitric oxide (NO) to the major ozone destroying gas nitrous oxide (N(2)O). Cryo–electron microscopy structures of active qNOR from Alcaligenes xylosoxidans and an activity-enhancing mutant have been determined to be at local resolutions of 3.7 and 3.2 Å, respectively. They unexpectedly reveal a dimeric conformation (also confirmed for qNOR from Neisseria meningitidis) and define the active-site configuration, with a clear water channel from the cytoplasm. Structure-based mutagenesis has identified key residues involved in proton transport and substrate delivery to the active site of qNORs. The proton supply direction differs from cytochrome c–dependent NOR (cNOR), where water molecules from the cytoplasm serve as a proton source similar to those from cytochrome c oxidase.
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spelling pubmed-67134972019-09-05 Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy Gopalasingam, Chai C. Johnson, Rachel M. Chiduza, George N. Tosha, Takehiko Yamamoto, Masaki Shiro, Yoshitsugu Antonyuk, Svetlana V. Muench, Stephen P. Hasnain, S. Samar Sci Adv Research Articles Quinol-dependent nitric oxide reductases (qNORs) are membrane-integrated, iron-containing enzymes of the denitrification pathway, which catalyze the reduction of nitric oxide (NO) to the major ozone destroying gas nitrous oxide (N(2)O). Cryo–electron microscopy structures of active qNOR from Alcaligenes xylosoxidans and an activity-enhancing mutant have been determined to be at local resolutions of 3.7 and 3.2 Å, respectively. They unexpectedly reveal a dimeric conformation (also confirmed for qNOR from Neisseria meningitidis) and define the active-site configuration, with a clear water channel from the cytoplasm. Structure-based mutagenesis has identified key residues involved in proton transport and substrate delivery to the active site of qNORs. The proton supply direction differs from cytochrome c–dependent NOR (cNOR), where water molecules from the cytoplasm serve as a proton source similar to those from cytochrome c oxidase. American Association for the Advancement of Science 2019-08-28 /pmc/articles/PMC6713497/ /pubmed/31489376 http://dx.doi.org/10.1126/sciadv.aax1803 Text en Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY). http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Gopalasingam, Chai C.
Johnson, Rachel M.
Chiduza, George N.
Tosha, Takehiko
Yamamoto, Masaki
Shiro, Yoshitsugu
Antonyuk, Svetlana V.
Muench, Stephen P.
Hasnain, S. Samar
Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy
title Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy
title_full Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy
title_fullStr Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy
title_full_unstemmed Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy
title_short Dimeric structures of quinol-dependent nitric oxide reductases (qNORs) revealed by cryo–electron microscopy
title_sort dimeric structures of quinol-dependent nitric oxide reductases (qnors) revealed by cryo–electron microscopy
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6713497/
https://www.ncbi.nlm.nih.gov/pubmed/31489376
http://dx.doi.org/10.1126/sciadv.aax1803
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