Crystal structure of higher plant heme oxygenase-1 and its mechanism of interaction with ferredoxin.

Autor:	Tohda R; Institute for Protein Research, Osaka University, Suita, Osaka, Japan; Department of Macromolecular Science, Osaka University, Toyonaka, Osaka, Japan., Tanaka H; Institute for Protein Research, Osaka University, Suita, Osaka, Japan; Department of Macromolecular Science, Osaka University, Toyonaka, Osaka, Japan., Mutoh R; Institute for Protein Research, Osaka University, Suita, Osaka, Japan., Zhang X; Graduate School of Medical Science, Yamagata University, Yamagata, Yamagata, Japan., Lee YH; Research Center of Bioconvergence Analysis, Korea Basic Science Institute, Cheongju, Chungbuk, South Korea; Graduate School of Analytical Science and Technology, Chungnam National University, Yuseong-gu, Daejeon, South Korea; Research Headquarters, Korea Brain Research Institute, Dong-gu, Daegu, South Korea; Bio-Analytical Science, University of Science and Technology, Yuseong-gu, Daejeon, South Korea., Konuma T; Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama, Japan., Ikegami T; Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama, Japan., Migita CT; Department of Biological Chemistry, Yamaguchi University, Yoshida, Yamaguchi, Japan., Kurisu G; Institute for Protein Research, Osaka University, Suita, Osaka, Japan; Department of Macromolecular Science, Osaka University, Toyonaka, Osaka, Japan. Electronic address: gkurisu@protein.osaka-u.ac.jp.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2021 Jan-Jun; Vol. 296, pp. 100217. Date of Electronic Publication: 2020 Dec 24.
DOI:	10.1074/jbc.RA120.016271
Abstrakt:	Heme oxygenase (HO) converts heme to carbon monoxide, biliverdin, and free iron, products that are essential in cellular redox signaling and iron recycling. In higher plants, HO is also involved in the biosynthesis of photoreceptor pigment precursors. Despite many common enzymatic reactions, the amino acid sequence identity between plant-type and other HOs is exceptionally low (∼19.5%), and amino acids that are catalytically important in mammalian HO are not conserved in plant-type HOs. Structural characterization of plant-type HO is limited to spectroscopic characterization by electron spin resonance, and it remains unclear how the structure of plant-type HO differs from that of other HOs. Here, we have solved the crystal structure of Glycine max (soybean) HO-1 (GmHO-1) at a resolution of 1.06 Å and carried out the isothermal titration calorimetry measurements and NMR spectroscopic studies of its interaction with ferredoxin, the plant-specific electron donor. The high-resolution X-ray structure of GmHO-1 reveals several novel structural components: an additional irregularly structured region, a new water tunnel from the active site to the surface, and a hydrogen-bonding network unique to plant-type HOs. Structurally important features in other HOs, such as His ligation to the bound heme, are conserved in GmHO-1. Based on combined data from X-ray crystallography, isothermal titration calorimetry, and NMR measurements, we propose the evolutionary fine-tuning of plant-type HOs for ferredoxin dependency in order to allow adaptation to dynamic pH changes on the stroma side of the thylakoid membrane in chloroplast without losing enzymatic activity under conditions of fluctuating light. Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article. (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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