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Summary Abscisic acid (ABA) receptors belong to theSTARTdomain superfamily, which encompasses ligand‐binding proteins present in all kingdoms of life.STARTdomain proteins contain a central binding pocket that, depending on the protein, can couple ligand binding to catalytic, transport or signaling functions. In Arabidopsis, the best characterizedSTARTdomain proteins are the 14PYR/PYL/RCAR ABAreceptors, while the other members of the superfamily do not have assigned ligands. To address this, we used affinity purification of biotinylated proteins expressed transiently inNicotiana benthamianacoupled to untargetedLC‐MSto identify candidate binding ligands. We optimized this method usingABA–PYLinteractions and show thatABAco‐purifies with wild‐typePYL5 but not a binding site mutant. TheKdofPYL5 forABAis 1.1 μm, which suggests that the method has sufficient sensitivity for many ligand–protein interactions. Using this method, we surveyed a set of 37STARTdomain‐related proteins, which resulted in the identification of ligands that co‐purified withMLBP1 (At4G01883) orMLP165 (At1G35260). Metabolite identification and the use of authentic standards revealed thatMLBP1 binds to monolinolenin, which we confirmed using recombinantMLBP1. Monolinolenin also co‐purified withMLBP1 purified from transgenic Arabidopsis, demonstrating that the interaction occurs in a native context. Thus, deployment of this relatively simple method allowed us to define a protein–metabolite interaction and better understand protein–ligand interactions in plants.
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Transport properties of disordered two‐dimensional complex plasma crystal
In this study, we numerically investigate the transport properties of a two‐dimensional (2D) complex plasma crystal using diffusion of coplanar dust lattice waves. In the limit where the Hamiltonian interactions can be decoupled from the non‐Hamiltonian effects, we identify two distinct types of wave transport: Anderson‐type delocalization and long‐distance excitation. We use a recently developed spectral approach to evaluate the contribution of the Anderson problem and compare it to the results of the simulation. The benefit of our approach to transport problems is twofold. First, we employ a highly tuneable macroscopic hexagonal crystal, which exhibits many‐body interactions and allows for the investigation of transport properties at the kinetic level. Second, the analysis of the transport problem in2Dis provided using an innovative spectral approach, which avoids the use of scaling and boundary conditions. The comparison between the analytically predicted and numerically observed wave dynamics allows for the study of important characteristics of this open system. In our simulations, we observe long‐distance lattice excitation, which occurs around lattice defects even when the initial perturbation does not spread from the centre to the exterior of the crystal. In the decoupled Hamiltonian regime, this many‐body effect can be attributed to the dust lattice interaction with the plasma environment.
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- PAR ID:
- 10049001
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Contributions to Plasma Physics
- Volume:
- 58
- Issue:
- 2-3
- ISSN:
- 0863-1042
- Page Range / eLocation ID:
- p. 209-216
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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