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Title: Crystal structure of the CueO mutants at Glu506, the key amino acid located in the proton transfer pathway for dioxygen reduction

Highlights: •Proton transfer pathway in the four-electron reduction of dioxygen by CueO. •Compensatory hydrogen bond network comprised of only water molecules in the Glu to Ala mutant. •Shutdown of the hydrogen bond network by the Glu to Ile mutation. •X-ray crystal structures of the CueO mutants with the modified proton transport pathway. -- Abstract: Glu506 involved in the hydrogen bond network leading from solvent waters to the trinuclear copper center in a multicopper oxidase, CueO plays a crucial role to transport protons in the four-electron reduction of dioxygen to water. We performed X-ray crystal structure analyses of the Glu506Ala and Glu506Ile mutants, showing the formation of a compensatory proton transport pathway with only water molecules and a disruption of the hydrogen bond network due to the bulky side chain, respectively. We discuss the efficiency of proton transport through the hydrogen bond network based on the present results and our previous modification of the proton transport pathway by the Glu506 to Gln mutation, which have allowed us to trap and characterize the reaction intermediates.
Authors:
 [1] ; ;  [2] ;  [3] ;  [2]
  1. Faculty of Education, Kagawa University, 1-1 Saiwai, Takamatsu 760-8522 (Japan)
  2. Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan)
  3. Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako 678-1297 (Japan)
Publication Date:
OSTI Identifier:
22242081
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 438; Journal Issue: 4; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; AMINO ACIDS; COPPER; CRYSTAL STRUCTURE; HYDROGEN; MOLECULES; MUTANTS; MUTATIONS; OXIDASES; PROTON TRANSPORT; PROTONS; REACTION INTERMEDIATES