2vy2
Structure of LEAFY transcription factor from Arabidopsis thaliana in complex with DNA from AG-I promoter
Structural highlights
FunctionLFY_ARATH Probable transcription factor that promotes early floral meristem identity in synergy with APETALA1. Is required subsequently for the transition of an inflorescence meristem into a floral meristem, by an immediate upstream regulation of the ABC classes of floral homeotic genes. Activates directly APETALA1, CAULIFLOWER and AGAMOUS, and indirectly APETALA3 and PISTILLATA with the cooperation of UFO.[REFERENCE:6][1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe LEAFY (LFY) protein is a key regulator of flower development in angiosperms. Its gradually increased expression governs the sharp floral transition, and LFY subsequently controls the patterning of flower meristems by inducing the expression of floral homeotic genes. Despite a wealth of genetic data, how LFY functions at the molecular level is poorly understood. Here, we report crystal structures for the DNA-binding domain of Arabidopsis thaliana LFY bound to two target promoter elements. LFY adopts a novel seven-helix fold that binds DNA as a cooperative dimer, forming base-specific contacts in both the major and minor grooves. Cooperativity is mediated by two basic residues and plausibly accounts for LFY's effectiveness in triggering sharp developmental transitions. Our structure reveals an unexpected similarity between LFY and helix-turn-helix proteins, including homeodomain proteins known to regulate morphogenesis in higher eukaryotes. The appearance of flowering plants has been linked to the molecular evolution of LFY. Our study provides a unique framework to elucidate the molecular mechanisms underlying floral development and the evolutionary history of flowering plants. Structural basis for LEAFY floral switch function and similarity with helix-turn-helix proteins.,Hames C, Ptchelkine D, Grimm C, Thevenon E, Moyroud E, Gerard F, Martiel JL, Benlloch R, Parcy F, Muller CW EMBO J. 2008 Oct 8;27(19):2628-37. Epub 2008 Sep 11. PMID:18784751[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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