2MUK

1H, 13C, and 15N Chemical Shift Assignments for AUX/IAA17

2MUK の概要

• エントリーDOI: 10.2210/pdb2muk/pdb
• NMR情報: BMRB: 25217
• 分子名称: Auxin-responsive protein IAA17 (1 entity in total)
• 機能のキーワード: aux/iaa, transcription
• 由来する生物種: Arabidopsis thaliana (mouse-ear cress,thale-cress)
• 細胞内の位置: Nucleus: P93830
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 12801.70

構造登録者

Suh, J.,Han, M. (登録日: 2014-09-11, 公開日: 2014-12-17, 最終更新日: 2024-05-01)

主引用文献

Han, M.,Park, Y.,Kim, I.,Kim, E.H.,Yu, T.K.,Rhee, S.,Suh, J.Y.
Structural basis for the auxin-induced transcriptional regulation by Aux/IAA17.
Proc.Natl.Acad.Sci.USA, 111:18613-18618, 2014

PubMed Abstract: Auxin is the central hormone that regulates plant growth and organ development. Transcriptional regulation by auxin is mediated by the auxin response factor (ARF) and the repressor, AUX/IAA. Aux/IAA associates with ARF via domain III-IV for transcriptional repression that is reversed by auxin-induced Aux/IAA degradation. It has been known that Aux/IAA and ARF form homo- and hetero-oligomers for the transcriptional regulation, but what determines their association states is poorly understood. Here we report, to our knowledge, the first solution structure of domain III-IV of Aux/IAA17 (IAA17), and characterize molecular interactions underlying the homotypic and heterotypic oligomerization. The structure exhibits a compact β-grasp fold with a highly dynamic insert helix that is unique in Aux/IAA family proteins. IAA17 associates to form a heterogeneous ensemble of front-to-back oligomers in a concentration-dependent manner. IAA17 and ARF5 associate to form homo- or hetero-oligomers using a common scaffold and binding interfaces, but their affinities vary significantly. The equilibrium dissociation constants (KD) for homo-oligomerization are 6.6 μM and 0.87 μM for IAA17 and ARF5, respectively, whereas hetero-oligomerization reveals a ∼ 10- to ∼ 100-fold greater affinity (KD = 73 nM). Thus, individual homo-oligomers of IAA17 and ARF5 spontaneously exchange their subunits to form alternating hetero-oligomers for transcriptional repression. Oligomerization is mainly driven by electrostatic interactions, so that charge complementarity at the interface determines the binding affinity. Variable binding affinity by surface charge modulation may effectively regulate the complex interaction network between Aux/IAA and ARF family proteins required for the transcriptional control of auxin-response genes.

PubMed: 25512488
DOI: 10.1073/pnas.1419525112

実験手法

SOLUTION NMR