Structural basis for prereceptor modulation of plant hormones by GH3 proteins.
Acyl acid amido synthetases of the GH3 family act as critical prereceptor modulators of plant hormone action; however, the molecular basis for their hormone selectivity is unclear. Here, we report the crystal structures of benzoate-specific Arabidopsis thaliana AtGH3.12/PBS3 and jasmonic acid-specific AtGH3.11/JAR1. These structures, combined with biochemical analysis, define features for the conjugation of amino acids to diverse acyl acid substrates and highlight the importance of conformational changes in the carboxyl-terminal domain for catalysis. We also identify residues forming the acyl acid binding site across the GH3 family and residues critical for amino acid recognition. Our results demonstrate how a highly adaptable three-dimensional scaffold is used for the evolution of promiscuous activity across an enzyme family for modulation of plant signaling molecules.
Department of Biology, Washington University, St. Louis, MO 63130, USA.
Corey S
CS
Westfall
Chloe
C
Zubieta
Jonathan
J
Herrmann
Ulrike
U
Kapp
Max H
MH
Nanao
Joseph M
JM
Jez
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism; D001565:Benzoates / Q000737:chemistry; D001665:Binding Sites; D018360:Crystallography, X-Ray; D003517:Cyclopentanes / Q000737:chemistry; D007210:Indoleacetic Acids / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000737:chemistry* / Q000378:metabolism; D054883:Oxylipins / Q000737:chemistry; D010937:Plant Growth Regulators / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D010453:Peptide Synthases
D000596:Amino Acids; D029681:Arabidopsis Proteins; D001565:Benzoates; D003517:Cyclopentanes; D007210:Indoleacetic Acids; D009713:Nucleotidyltransferases; D054883:Oxylipins; D010937:Plant Growth Regulators; C523087:At5g13320 protein, Arabidopsis; C011006:jasmonic acid; C412831:AT2G46370 protein, Arabidopsis; D010453:Peptide Synthases