2MUK

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


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural basis for the auxin-induced transcriptional regulation by Aux/IAA17.

Han, M.Park, Y.Kim, I.Kim, E.H.Yu, T.K.Rhee, S.Suh, J.Y.

(2014) Proc.Natl.Acad.Sci.USA 111: 18613-18618

  • DOI: 10.1073/pnas.1419525112

  • 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 transcrip ...

    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.


    Organizational Affiliation

    Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Gwanak-gu, Seoul 151-921, Republic of Korea; and.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Auxin-responsive protein IAA17
X
113Arabidopsis thalianaGene Names: IAA17 (AXR3)
Find proteins for P93830 (Arabidopsis thaliana)
Go to UniProtKB:  P93830
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2014-09-11 
  • Released Date: 2014-12-17 
  • Deposition Author(s): Suh, J., Han, M.

Revision History 

  • Version 1.0: 2014-12-17
    Type: Initial release
  • Version 1.1: 2015-01-14
    Type: Database references