Defining a two-pronged structural model for PB1 (Phox/Bem1p) domain interaction in plant auxin responses.

Journal Article (Journal Article)

Phox/Bem1p (PB1) domains are universal structural modules that use surfaces of different charge for protein-protein association. In plants, PB1-mediated interactions of auxin response factors (ARF) and auxin/indole 3-acetic acid inducible proteins regulate transcriptional events modulated by the phytohormone auxin. Here we investigate the thermodynamic and structural basis for Arabidopsis thaliana ARF7 PB1 domain self-interaction. Isothermal titration calorimetry and NMR experiments indicate that key residues on both the basic and acidic faces of the PB1 domain contribute to and organize coordinately to stabilize protein-protein interactions. Calorimetric analysis of ARF7PB1 site-directed mutants defines a two-pronged electrostatic interaction. The canonical PB1 interaction between a lysine and a cluster of acidic residues provides one prong with an arginine and a second cluster of acidic residues defining the other prong. Evolutionary conservation of this core recognition feature and other co-varying interface sequences allows for versatile PB1-mediated interactions in auxin signaling.

Full Text

Duke Authors

Cited Authors

  • Korasick, DA; Chatterjee, S; Tonelli, M; Dashti, H; Lee, SG; Westfall, CS; Fulton, DB; Andreotti, AH; Amarasinghe, GK; Strader, LC; Jez, JM

Published Date

  • May 2015

Published In

Volume / Issue

  • 290 / 20

Start / End Page

  • 12868 - 12878

PubMed ID

  • 25839233

Pubmed Central ID

  • PMC4432302

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.m115.648253


  • eng