7AAS

Crystal structure of nitrosoglutathione reductase (GSNOR) from Chlamydomonas reinhardtii

7AAS の概要

• エントリーDOI: 10.2210/pdb7aas/pdb
• 分子名称: S-(hydroxymethyl)glutathione dehydrogenase, ZINC ION, DI(HYDROXYETHYL)ETHER, ... (5 entities in total)
• 機能のキーワード: alcohol dehydrogenase, zinc-binding dehydrogenase, oxidoreductase
• 由来する生物種: Chlamydomonas reinhardtii
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 244967.83

構造登録者

Fermani, S.,Zaffagnini, M.,Falini, G.,Lemaire, S.D. (登録日: 2020-09-04, 公開日: 2020-12-30, 最終更新日: 2024-01-31)

主引用文献

Tagliani, A.,Rossi, J.,Marchand, C.H.,De Mia, M.,Tedesco, D.,Gurrieri, L.,Meloni, M.,Falini, G.,Trost, P.,Lemaire, S.D.,Fermani, S.,Zaffagnini, M.
Structural and functional insights into nitrosoglutathione reductase from Chlamydomonas reinhardtii.
Redox Biol, 38:101806-101806, 2020

PubMed Abstract: Protein S-nitrosylation plays a fundamental role in cell signaling and nitrosoglutathione (GSNO) is considered as the main nitrosylating signaling molecule. Enzymatic systems controlling GSNO homeostasis are thus crucial to indirectly control the formation of protein S-nitrosothiols. GSNO reductase (GSNOR) is the key enzyme controlling GSNO levels by catalyzing its degradation in the presence of NADH. Here, we found that protein extracts from the microalga Chlamydomonas reinhardtii catabolize GSNO via two enzymatic systems having specific reliance on NADPH or NADH and different biochemical features. Scoring the Chlamydomonas genome for orthologs of known plant GSNORs, we found two genes encoding for putative and almost identical GSNOR isoenzymes. One of the two, here named CrGSNOR1, was heterologously expressed and purified. Its kinetic properties were determined and the three-dimensional structures of the apo-, NAD- and NAD/GSNO-forms were solved. These analyses revealed that CrGSNOR1 has a strict specificity towards GSNO and NADH, and a conserved folding with respect to other plant GSNORs. The catalytic zinc ion, however, showed an unexpected variability of the coordination environment. Furthermore, we evaluated the catalytic response of CrGSNOR1 to thermal denaturation, thiol-modifying agents and oxidative modifications as well as the reactivity and position of accessible cysteines. Despite being a cysteine-rich protein, CrGSNOR1 contains only two solvent-exposed/reactive cysteines. Oxidizing and nitrosylating treatments have null or limited effects on CrGSNOR1 activity and folding, highlighting a certain resistance of the algal enzyme to redox modifications. The molecular mechanisms and structural features underlying the response to thiol-based modifications are discussed.

PubMed: 33316743
DOI: 10.1016/j.redox.2020.101806

実験手法

X-RAY DIFFRACTION (1.8 Å)