6E1Q

AtGH3.15 acyl acid amido synthetase in complex with 2,4-DB

Summary for 6E1Q

• Entry DOI: 10.2210/pdb6e1q/pdb
• Descriptor: AtGH3.15 acyl acid amido synthetase, PHOSPHATE ION, (2,4-DICHLOROPHENOXY)ACETIC ACID, ... (4 entities in total)
• Functional Keywords: hormone modification, adenylating enzyme, acyl acid-amido synthetase, adenylation, ligase, plant protein
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 1
• Total formula weight: 67589.51

Authors

Sharp, A.M.,Lee, S.G.,Jez, J.M. (deposition date: 2018-07-10, release date: 2018-10-24, Last modification date: 2024-11-13)

Primary citation

Sherp, A.M.,Lee, S.G.,Schraft, E.,Jez, J.M.
Modification of auxinic phenoxyalkanoic acid herbicides by the acyl acid amido synthetase GH3.15 from Arabidopsis.
J. Biol. Chem., 293:17731-17738, 2018

PubMed Abstract: Herbicide-resistance traits are the most widely used agriculture biotechnology products. Yet, to maintain their effectiveness and to mitigate selection of herbicide-resistant weeds, the discovery of new resistance traits that use different chemical modes of action is essential. In plants, the Gretchen Hagen 3 (GH3) acyl acid amido synthetases catalyze the conjugation of amino acids to jasmonate and auxin phytohormones. This reaction chemistry has not been explored as a possible approach for herbicide modification and inactivation. Here, we examined a set of Arabidopsis GH3 proteins that use the auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) as substrates along with the corresponding auxinic phenoxyalkanoic acid herbicides 2,4-dichlorophenoxylacetic acid (2,4-D) and 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB). The IBA-specific AtGH3.15 protein displayed high catalytic activity with 2,4-DB, which was comparable to its activity with IBA. Screening of phenoxyalkanoic and phenylalkyl acids indicated that side-chain length of alkanoic and alkyl acids is a key feature of AtGH3.15's substrate preference. The X-ray crystal structure of the AtGH3.15·2,4-DB complex revealed how the herbicide binds in the active site. In root elongation assays, Arabidopsis AtGH3.15-knockout and -overexpression lines grown in the presence of 2,4-DB exhibited hypersensitivity and tolerance, respectively, indicating that the AtGH3.15-catalyzed modification inactivates 2,4-DB. These findings suggest a potential use for AtGH3.15, and perhaps other GH3 proteins, as herbicide-modifying enzymes that employ a mode of action different from those of currently available herbicide-resistance traits.

PubMed: 30315112
DOI: 10.1074/jbc.RA118.004975

Experimental method

X-RAY DIFFRACTION (2.148 Å)