Interactions between indole-3-acetic acid (IAA) with a lectin from Canavalia maritima seeds reveal a new function for lectins in plant physiology

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• 作者：Plinio Delatorre ; Jos¨¦ Caetano Silva-Filho ; Bruno Anderson Matias Rocha ; Tatiane Santi-Gadelha ; Raphael Batista da N¨®brega ; Carlos Alberto Almeida Gadelha ; Kyria Santiago do Nascimento ; Celso Shiniti Nagano ; Alex ; re Hol ; a Sampaio ; Benildo Sousa Cavada
• 关键词：Lectin ; Indole-acetic acid ; Canavalia maritima
• 刊名：Biochimie
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：95
• 期：9
• 页码：1697-1703
• 全文大小：1230 K

文摘

Indole-3-acetic acid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15?? resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for legume lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination.