High-Resolution Crystal Structure of Arabidopsis FLOWERING LOCUS T Illuminates Its Phospholipid-Binding Site in Flowering
Yuki Nakamura,
Ying-Chen Lin,
Satoshi Watanabe,
Yu-chi Liu,
Kentaro Katsuyama,
Kazue Kanehara,
Kenji Inaba
Affiliations
Yuki Nakamura
Institute of Plant and Microbial Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan; Corresponding author
Ying-Chen Lin
Institute of Plant and Microbial Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
Satoshi Watanabe
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
Yu-chi Liu
Institute of Plant and Microbial Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
Kentaro Katsuyama
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
Kazue Kanehara
Institute of Plant and Microbial Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
Kenji Inaba
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan; CREST, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan; Corresponding author
Summary: Arabidopsis FLOWERING LOCUS T (FT) is a pivotal component of florigen, a long-range mobile flowering signal. Here, we determined the 1.0 Å-resolution crystal structure of FT, a significantly higher-resolution crystal structure of FT than previously reported one (2.6 Å). The present crystallographic studies revealed 4 alternative configurations with the precise location of the surrounding water molecules. Using this structural data, computational docking simulation predicted the putative binding sites for phosphatidylcholine (PC), an endogenous ligand that interacts with FT to modulate flowering time. In vitro reconstitution of the lipid–protein interaction showed that mutations at two of the predicted sites significantly compromised the lipid binding ability of FT. In planta, one of the mutant FT proteins significantly affected FT function in flowering, emphasizing the involvement of PC binding in modulating FT function. Our structural, biochemical, and transgenic analyses reveal the molecular mechanism of PC binding in FT-mediated flowering time control. : Biological Sciences; Plant Biochemistry; Structural Biology; Plant Biology Subject Areas: Biological Sciences, Plant Biochemistry, Structural Biology, Plant Biology
