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Crystal structure of dioxygenase for auxin oxidation (DAO) in riceCrystal structure of dioxygenase for auxin oxidation (DAO) in rice
Structural highlights
Publication Abstract from PubMedAllosteric regulation is protein activation by effector binding at a site other than the active site. Here, we show via X-ray structural analysis of gibberellin 2-oxidase 3 (GA2ox3), and auxin dioxygenase (DAO), that such a mechanism maintains hormonal homeostasis in plants. Both enzymes form multimers by interacting via GA4 and indole-3-acetic acid (IAA) at their binding interface. Via further functional analyses we reveal that multimerization of these enzymes gradually proceeds with increasing GA4 and IAA concentrations; multimerized enzymes have higher specific activities than monomer forms, a system that should favour the maintenance of homeostasis for these phytohormones. Molecular dynamic analysis suggests a possible mechanism underlying increased GA2ox3 activity by multimerization-GA4 in the interface of oligomerized GA2ox3s may be able to enter the active site with a low energy barrier. In summary, homeostatic systems for maintaining GA and IAA levels, based on a common allosteric mechanism, appear to have developed independently. A common allosteric mechanism regulates homeostatic inactivation of auxin and gibberellin.,Takehara S, Sakuraba S, Mikami B, Yoshida H, Yoshimura H, Itoh A, Endo M, Watanabe N, Nagae T, Matsuoka M, Ueguchi-Tanaka M Nat Commun. 2020 May 1;11(1):2143. doi: 10.1038/s41467-020-16068-0. PMID:32358569[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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