Structural basis for gibberellin recognition by its receptor GID1

• Published in: Nature (London) Vol. 456; no. 7221; pp. 520 - 523
• Main Authors: Shimada, Asako, Ueguchi-Tanaka, Miyako, Nakatsu, Toru, Nakajima, Masatoshi, Naoe, Youichi, Ohmiya, Hiroko, Kato, Hiroaki, Matsuoka, Makoto
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 27.11.2008
• Subjects: Arabidopsis thaliana; Binding Sites; Biochemistry; Biological and medical sciences; Cell receptors; Cell structures and functions; crystal structure; Crystalline structure; Crystallography, X-Ray; Enzymes; Fundamental and applied biological sciences. Psychology; gene expression regulation; Gibberellins; Gibberellins - chemistry; Gibberellins - metabolism; GID1 receptor; Hydrolases - chemistry; Hydrolases - metabolism; Hydroxylation; Miscellaneous; Models, Molecular; Molecular and cellular biology; Molecular biophysics; Molecules; Oryza - chemistry; Oryza - genetics; Oryza - metabolism; Physiological aspects; Plant growth; Plant Growth Regulators - chemistry; Plant Growth Regulators - metabolism; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Protein Binding; Protein Conformation; protein structure; protein-protein interactions; Proteins; receptors; Structure; Structure in molecular biology; Substrate Specificity; transcription factors; Two-Hybrid System Techniques; Japan; Oryza sativa; Monocotyledones; Three dimensional structure; Gramineae; Angiospermae; Gibberellin; Spermatophyta; Molecular complex; Recognition; Biological receptor; Crystalline structure
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature07546

Gibberellins (GAs) are phytohormones essential for many developmental processes in plants. A nuclear GA receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), has a primary structure similar to that of the hormone-sensitive lipases (HSLs). Here we analyse the crystal structure of Oryza sativa GID1 (OsGID1) bound with GA4 and GA3 at 1.9 Å resolution. The overall structure of both complexes shows an / -hydrolase fold similar to that of HSLs except for an amino-terminal lid. The GA-binding pocket corresponds to the substrate-binding site of HSLs. On the basis of the OsGID1 structure, we mutagenized important residues for GA binding and examined their binding activities. Almost all of them showed very little or no activity, confirming that the residues revealed by structural analysis are important for GA binding. The replacement of Ile 133 with Leu or Val-residues corresponding to those of the lycophyte Selaginella moellendorffii GID1s-caused an increase in the binding affinity for GA34, a 2 -hydroxylated GA4. These observations indicate that GID1 originated from HSL and was further modified to have higher affinity and more strict selectivity for bioactive GAs by adapting the amino acids involved in GA binding in the course of plant evolution.