Crystal Structure and Molecular Mechanism of Isocitrate Lyase from Chloroflexus aurantiacus

被引：0

作者：

Lee, Seul Hoo ^{[2
]}

Park, Jiyoung ^{[1
]}

Kim, Kyung-Jin ^{[1
,2
]}

机构：

[1] School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu,41566, Korea, Republic of

[2] KNU Institute for Microorganisms, Kyungpook National University, Daegu,41566, Korea, Republic of

来源：

Journal of Agricultural and Food Chemistry | 2024年

基金：

新加坡国家研究基金会;

关键词：

Carbon fixation - Carbon fixation bacteria - Catalytic loop movement - Catalytic mechanisms - Chloroflexus aurantiacus - Crystals structures - Isocitrate lyase - Isocitrates - Loop movement - Molecular mechanism;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Chloroflexus aurantiacus is a green, nonsulfur bacterium that employs the 3-hydroxypropionate cycle to grow, using carbon dioxide/bicarbonate as its primary carbon source. Like most bacteria, it possesses the glyoxylate cycle, facilitated by malate synthase and isocitrate lyase (ICL), allowing a tricarboxylic acid cycle bypass. C. aurantiacus also harbors ICL, an enzyme that catalyzes reversible isocitrate cleavage into glyoxylate and succinate. This study presents the crystal structures of C. aurantiacus-derived ICL (CaICL), in its Mg2+-bound and Mn2+ and isocitrate-bound forms, elucidating its substrate-binding mechanism and catalytic loop dynamics. CaICL forms a homotetramer and interacts with isocitrate via critical active-site residues, revealing its catalytic mechanism. The stabilization of the catalytic loop and adjacent terminal regions upon isocitrate binding underscores its functional significance. These findings advance our understanding regarding ICL enzymes, offering a basis for future investigations into their biological roles and potential applications. © 2024 American Chemical Society.

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