In plants, GH3 proteins act as molecular on/off switches that control bioactive plant hormone formation by catalyzing the addition of specific amino acids to jasmonic acid, auxin, and benzoates. X-ray structures of GH3 proteins reveal a common three-dimensional fold but variability in the hormone binding site. This figure shows the variation in the jasmonic acid binding site of Arabidopsis thaliana GH3.11/JAR1 (gold) and the salicylic acid binding site of A. thaliana GH3.12/PBS3 (green).
Westfall, C. S., et al. 2012. “Structural Basis for Prereceptor Modulation of Plant Hormones by GH3 Proteins,” Science 336, 1708–11. DOI: 10.1126/science.1221863
Funding Acknowledgements: Work supported by National Science Foundation (NSF) grant MCB-1157771 to J.M.J. C.S.W. supported by U.S. Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) predoctoral fellowship (MOW-2010-05240), and J.H. supported by American Society of Plant Biologists (ASPB) Summer Undergraduate Research Fellowship award and the Howard Hughes Medical Institute (HHMI)–Washington University in St. Louis Summer Scholars Program in Biology and Biomedical Research. Portions of this research carried out at European Synchrotron Radiation Facility (ESRF) and Argonne National Laboratory (ANL) Structural Biology Center (SBC) of the Advanced Photon Source (APS), a national user facility operated by the University of Chicago for the Office of Biological and Environmental Research, U.S. Department of Energy (DOE) Office of Science (DE-AC02-06CH11357). Atomic coordinates and structure factors deposited in Protein Data Bank (PDB; accession codes noted in table S2).