5gwo
Crystal structure of RCAR3:PP2C S265F/I267M with (+)-ABA
Structural highlights
FunctionPublication Abstract from PubMedAbscisic acid (ABA) signaling pathway is regulated by Clade A type 2C protein phosphatases (PP2CAs) in plant. In the presence of ABA, PP2Cs release stress/ABA-activated protein kinases by binding to ABA-bound receptors (PYL/RCARs) for activation. Although the wedging tryptophan in PP2Cs is critical in the interaction with PYL/RCARs in Arabidopsis and rice, it remains elusive how other interface regions are involved in the interaction. Here, we identified a conserved region on PP2Cs, termed VxGPhiL motif, that modulates the interaction with PYL/RCARs through its second and forth residues. The effects of the second and forth residues on the interaction of OsPP2C50 with several OsPYL/RCAR proteins were investigated by systematic mutagenesis. Investigating the interaction between OsPP2C50 and OsPYL/RCAR3, one OsPP2C50 mutant, VFGML ("FM") mutant, lowered the affinity by approximately 15-fold. Comparison of the crystal structures of OsPP2C50:ABA:OsPYL/RCAR3 wild-type and FM mutant revealed local conformational changes near the VxGPhiL motif, further supported by hydrogen-deuterium exchange mass spectrometry. In rice protoplasts, ABA signaling was altered by mutations in the VxGPhiL motif. Transgenic Arabidopsis plants overexpressing OsPP2C50 and OsPP2C50FM changed ABA sensitivity, validating the in vitro results. Taken together, the VxGPhiL motif of PP2Cs seems to modulate the affinity to PYL/RCARs with potentials to alter the ABA signaling, leading to the differential sensitivity to ABA in planta. Modulation of ABA signaling by altering VxGPhiL motif of PP2Cs in Oryza sativa.,Han S, Min MK, Lee SY, Lim CW, Bhatnagar N, Lee Y, Shin D, Chung KY, Lee SC, Kim BG, Lee S Mol Plant. 2017 Aug 18. pii: S1674-2052(17)30233-2. doi:, 10.1016/j.molp.2017.08.003. PMID:28827170[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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