7D3Y

Crystal structure of the osPHR2-osSPX2 complex

Summary for 7D3Y

• Entry DOI: 10.2210/pdb7d3y/pdb
• Descriptor: SPX domain-containing protein 2,Isoform 1 of Core histone macro-H2A.1, Protein PHOSPHATE STARVATION RESPONSE 2, INOSITOL HEXAKISPHOSPHATE (3 entities in total)
• Functional Keywords: protein phosphate starvation response 2, myb, dna binding protein, spx2
• Biological source: Oryza sativa subsp. indica (Rice); More
• Total number of polymer chains: 5
• Total formula weight: 138623.04

Authors

Zhang, Q.X.,Guan, Z.Y.,Zuo, J.Q.,Zhang, Z.F.,Liu, Z. (deposition date: 2020-09-21, release date: 2021-10-06, Last modification date: 2023-11-29)

Primary citation

Guan, Z.,Zhang, Q.,Zhang, Z.,Zuo, J.,Chen, J.,Liu, R.,Savarin, J.,Broger, L.,Cheng, P.,Wang, Q.,Pei, K.,Zhang, D.,Zou, T.,Yan, J.,Yin, P.,Hothorn, M.,Liu, Z.
Mechanistic insights into the regulation of plant phosphate homeostasis by the rice SPX2 - PHR2 complex.
Nat Commun, 13:1581-1581, 2022

PubMed Abstract: Phosphate (Pi) starvation response (PHR) transcription factors play key roles in plant Pi homeostasis maintenance. They are negatively regulated by stand-alone SPX proteins, cellular receptors for inositol pyrophosphate (PP-InsP) nutrient messengers. How PP-InsP-bound SPX interacts with PHRs is poorly understood. Here, we report crystal structures of the rice SPX2/InsP/PHR2 complex and of the PHR2 DNA binding (MYB) domain in complex with target DNA at resolutions of 3.1 Å and 2.7 Å, respectively. In the SPX2/InsP/PHR2 complex, the signalling-active SPX2 assembles into a domain-swapped dimer conformation and binds two copies of PHR2, targeting both its coiled-coil (CC) oligomerisation domain and MYB domain. Our results reveal that the SPX2 senses PP-InsPs to inactivate PHR2 by establishing severe steric clashes with the PHR2 MYB domain, preventing DNA binding, and by disrupting oligomerisation of the PHR2 CC domain, attenuating promoter binding. Our findings rationalize how PP-InsPs activate SPX receptor proteins to target PHR family transcription factors.

PubMed: 35332155
DOI: 10.1038/s41467-022-29275-8

Experimental method

X-RAY DIFFRACTION (3.11 Å)