2hs8
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Crystal structure of the Y364F mutant of 12-oxophytodienoate reductase 3 from tomato
OverviewOverview
12-Oxophytodienoate reductase (OPR) 3, a homologue of old yellow enzyme, (OYE), catalyzes the reduction of 9S,13S-12-oxophytodienoate to the, corresponding cyclopentanone, which is subsequently converted to the plant, hormone jasmonic acid (JA). JA and JA derivatives, as well as, 12-oxophytodienoate and related cyclopentenones, are known to regulate, gene expression in plant development and defense. Together with other, oxygenated fatty acid derivatives, they form the oxylipin signature in, plants, which resembles the pool of prostaglandins in animals. Here, we, report the crystal structure of OPR3 from tomato and of two OPR3 mutants., Although the catalytic residues of OPR3 and related OYEs are highly, conserved, several characteristic differences can be discerned in the, substrate-binding regions, explaining the remarkable substrate, stereoselectivity of OPR isozymes. Interestingly, OPR3 crystallized as an, extraordinary self-inhibited dimer. Mutagenesis studies and biochemical, analysis confirmed a weak dimerization of OPR3 in vitro, which correlated, with a loss of enzymatic activity. Based on structural data of OPR3, a, putative mechanism for a strong and reversible dimerization of OPR3 in, vivo that involves phosphorylation of OPR3 is suggested. This mechanism, could contribute to the shaping of the oxylipin signature, which is, critical for fine-tuning gene expression in plants.
About this StructureAbout this Structure
2HS8 is a Single protein structure of sequence from Solanum lycopersicum with FMN as ligand. Active as 12-oxophytodienoate reductase, with EC number 1.3.1.42 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of 12-oxophytodienoate reductase 3 from tomato: self-inhibition by dimerization., Breithaupt C, Kurzbauer R, Lilie H, Schaller A, Strassner J, Huber R, Macheroux P, Clausen T, Proc Natl Acad Sci U S A. 2006 Sep 26;103(39):14337-42. Epub 2006 Sep 18. PMID:16983071
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