6OMS

Arabidopsis GH3.12 with Chorismate

Summary for 6OMS

• Entry DOI: 10.2210/pdb6oms/pdb
• Descriptor: 4-substituted benzoates-glutamate ligase GH3.12, ADENOSINE MONOPHOSPHATE, (3R,4R)-3-[(1-carboxyethenyl)oxy]-4-hydroxycyclohexa-1,5-diene-1-carboxylic acid, ... (4 entities in total)
• Functional Keywords: acyl acid-amido synthetase, ligase
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 2
• Total formula weight: 131302.24

Authors

Zubieta, C.,Westfall, C.S.,Holland, C.K.,Jez, J.M. (deposition date: 2019-04-19, release date: 2019-10-09, Last modification date: 2023-10-11)

Primary citation

Holland, C.K.,Westfall, C.S.,Schaffer, J.E.,De Santiago, A.,Zubieta, C.,Alvarez, S.,Jez, J.M.
Brassicaceae-specific Gretchen Hagen 3 acyl acid amido synthetases conjugate amino acids to chorismate, a precursor of aromatic amino acids and salicylic acid.
J.Biol.Chem., 294:16855-16864, 2019

PubMed Abstract: To modulate responses to developmental or environmental cues, plants use Gretchen Hagen 3 (GH3) acyl acid amido synthetases to conjugate an amino acid to a plant hormone, a reaction that regulates free hormone concentration and downstream responses. The model plant has 19 GH3 proteins, of which 8 have confirmed biochemical functions. One Brassicaceae-specific clade of GH3 proteins was predicted to use benzoate as a substrate and includes AtGH3.7 and AtGH3.12/PBS3. Previously identified as a 4-hydroxybenzoic acid-glutamate synthetase, AtGH3.12/PBS3 influences pathogen defense responses through salicylic acid. Recent work has shown that AtGH3.12/PBS3 uses isochorismate as a substrate, forming an isochorismate-glutamate conjugate that converts into salicylic acid. Here, we show that AtGH3.7 and AtGH3.12/PBS3 can also conjugate chorismate to cysteine and glutamate, which act as precursors to aromatic amino acids and salicylic acid, respectively. The X-ray crystal structure of AtGH3.12/PBS3 in complex with AMP and chorismate at 1.94 Å resolution, along with site-directed mutagenesis, revealed how the active site potentially accommodates this substrate. Examination of knockout lines indicated that the mutants do not alter growth and showed no increased susceptibility to the pathogen , unlike mutants, which were more susceptible than WT plants, as was the / double mutant. The findings of our study suggest that GH3 proteins can use metabolic precursors of aromatic amino acids as substrates.

PubMed: 31575658
DOI: 10.1074/jbc.RA119.009949

Experimental method

X-RAY DIFFRACTION (1.942 Å)