C2ドメインによって調節される多領域酸化窒素合成酵素の構造と動態

Dhruva Nair¹, Brian R Crane¹

¹Weill Institute for Cell and Molecular Biology, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.

Science advances

|February 20, 2026

まとめ

酸化窒素合成酵素 (NOS) の構造は,冷凍電子顕微鏡を用いて明らかにされました. この酵素は,

科学分野:

バイオケミストリーバイオケミストリー
構造生物学構造生物学とは
酵素学酵素学とは

背景:

酸化窒素合成酵素 (NOS) は,酸化窒素 (NO) を生成する重要な酵素です.
NOS酵素は,ダイナミックなドメイン関連を持つ複雑な多領域構造を特徴としています.
完全なNOS酵素の詳細な構造的特徴付けは困難でした.

研究の目的:

代表的なサイアノバクテリアのNOSの全長アーキテクチャを明らかにする.
NOSのダイナミックな形状の変化と規制メカニズムを特徴付ける.

主な方法:

Cryo-electron microscopy (cryo-EM) が構造を決定するために使用されました.
複数の構造状態の分析により,酵素の動態が把握されました.

主要な成果:

この研究は, *Synechococcus* の二次元六ドメインのNOSの完全なアーキテクチャを明らかにした.
5つの異なる構造状態は,プテリン結合,オキシゲンアース構成,およびCa2+ 感受性C2ドメインの調節を示しています.
Ca2+感受性C2ドメインは,NOSとNODの両方のヘムセンターを調節する重要な動きを示します.

結論:

この調査結果は,NOS規制に関する前例のない構造的な洞察を提供している.
C2ドメインとカルボキシル末尾を含むダイナミック相互作用は,多ドメインのNOSで複雑な規制層を明らかにします.
この研究は,様々な生物学的プロセスにおけるNOSの機能の理解を進める.

さらに関連する動画

08:23

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Published on: February 16, 2022

4.9K

07:15

Measurement of Cyclic Guanosine Monophosphate (cGMP) in Solid Tissues using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)

Published on: July 3, 2025

736

関連する概念動画

01:28

Nitric Oxide Signaling Pathway

6.4K

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure...

6.4K

02:52

Resonance

67.4K

The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O bonds.

67.4K

01:18

ATP Synthase: Structure

15.9K

ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...

15.9K

01:30

Assembly of Signaling Complexes

6.7K

Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...

6.7K

02:26

Conservation of Protein Domains Over Different Proteins

14.8K

Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...

14.8K

01:19

Nitrosation of Enols

10.0K

The nitrosation reaction is one of the methods of preparing 1,2-diketones. The enol tautomer of the starting ketone reacts with sodium nitrite in hydrochloric acid, generating the 1,2-diketone after hydrolysis.