2026-04-30 筑波大学
メタノールをエネルギー源として利用する酵母において重要な役割を担う酵素の立体構造を、クライオ電子顕微鏡を用いて高精度で解明しました。その結果、よく似た構造の2種類の酵素が環境に応じて異なる働きをする仕組みが明らかとなりました。
＜関連情報＞
- https://www.tsukuba.ac.jp/journal/technology-materials/20260430140000.html
- https://enviromicro-journals.onlinelibrary.wiley.com/doi/10.1111/1751-7915.70355
Ogataea methanolica 由来アルコールオキシダーゼのクライオ電⼦顕微鏡構造による補酵素の多様性および酵素活性決定機構の解明 Cryo-EM Structures of Alcohol Oxidase Isozymes Reveal Structural Determinants of Cofactor Variation and Enzymatic Activity in Ogataea methanolica
Hao-Liang Cai, Atsuhiro Shimada, Tasuku Hamaguchi, Akira Mizoguchi, Koji Yonekura, Kyohei Tsuchiyama, Masaya Shimada, Akio Ebihara, Kazutoshi Tani, Tomoyuki Nakagawa
Microbial Biotechnology Published: 18 April 2026
DOI:https://doi.org/10.1111/1751-7915.70355
ABSTRACT
Ogataea methanolica is a methylotrophic yeast that can produce diverse recombinant proteins using methanol as the sole carbon and energy source. Unlike most yeast species, which possess a single alcohol oxidase, O. methanolica encodes two isoenzymes, Mod1p and Mod2p. This study examines the structural and functional differences between Mod1p and Mod2p homooctamers. Both enzymes were purified from MOD-disrupted strains and analysed using cryogenic electron microscopy, achieving resolutions of 1.9 and 2.7 Å for Mod1p and Mod2p, respectively. The two isozymes assemble as tetramers of dimers stabilized by extensive intersubunit interactions, largely mediated by protruding loop regions and C-terminal extensions. Despite overall structural similarities, Mod1p and Mod2p exhibit subtle differences in surface charge distribution and sequence composition within the FAD-binding domain. These variations correlate with distinct cofactor preferences, with Mod1p binding arabityl FAD and Mod2p binding canonical FAD. Thin-section electron microscopy further revealed that Mod1p and Mod2p form both homomeric and hybrid octamers that assemble into peroxisomal crystalloids essential for methanol metabolism. Collectively, our findings provide mechanistic insight into alcohol oxidase diversity in methylotrophic yeasts, advancing our understanding of methanol utilization and its applications in biotechnology.
