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The Strawberry Pathogenesis-related 10 (PR-10) Fra a Proteins Control Flavonoid Biosynthesis by Binding to Metabolic Intermediates
Pathogenesis-related 10 (PR-10) proteins are involved in many aspects of plant biology but their molecular function is still unclear. They are related by sequence and structural homology to mammalian lipid transport and plant abscisic acid receptor proteins and are predicted to have cavities for lig...
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Published in: | The Journal of biological chemistry 2013-12, Vol.288 (49), p.35322-35332 |
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Main Authors: | , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Pathogenesis-related 10 (PR-10) proteins are involved in many aspects of plant biology but their molecular function is still unclear. They are related by sequence and structural homology to mammalian lipid transport and plant abscisic acid receptor proteins and are predicted to have cavities for ligand binding. Recently, three new members of the PR-10 family, the Fra a proteins, have been identified in strawberry, where they are required for the activity of the flavonoid biosynthesis pathway, which is essential for the development of color and flavor in fruits. Here, we show that Fra a proteins bind natural flavonoids with different selectivity and affinities in the low μm range. The structural analysis of Fra a 1 E and a Fra a 3-catechin complex indicates that loops L3, L5, and L7 surrounding the ligand-binding cavity show significant flexibility in the apo forms but close over the ligand in the Fra a 3-catechin complex. Our findings provide mechanistic insight on the function of Fra a proteins and suggest that PR-10 proteins, which are widespread in plants, may play a role in the control of secondary metabolic pathways by binding to metabolic intermediates.
Background: Suppression of Fra a gene expression leads to down-regulation of color-producing flavonoid biosynthesis in strawberry.
Results: Fra proteins can bind natural flavonoids, which induce conformational changes in conserved loop regions.
Conclusion: Fra a proteins control flavonoid biosynthesis through binding to metabolic intermediates.
Significance: PR-10 proteins may play a role in the control of secondary metabolism through binding of metabolites to their ligand-binding cavities. |
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ISSN: | 0021-9258 1083-351X 1083-351X |
DOI: | 10.1074/jbc.M113.501528 |