5IJP

Crystal structure of the SPX domain of Chaetomium thermophilum Vtc4 in complex with inositol hexakisphosphate (InsP6).

Summary for 5IJP

• Entry DOI: 10.2210/pdb5ijp/pdb
• Descriptor: Putative uncharacterized protein, ACETATE ION, INOSITOL HEXAKISPHOSPHATE, ... (4 entities in total)
• Functional Keywords: helical bundle, alpha-helical hairpin, inositol phosphate binding protein, protein-protein interaction, structural protein
• Biological source: Chaetomium thermophilum
• Total number of polymer chains: 1
• Total formula weight: 24321.83

Authors

Wild, R.,Hothorn, M. (deposition date: 2016-03-02, release date: 2016-04-27, Last modification date: 2024-01-10)

Primary citation

Wild, R.,Gerasimaite, R.,Jung, J.Y.,Truffault, V.,Pavlovic, I.,Schmidt, A.,Saiardi, A.,Jessen, H.J.,Poirier, Y.,Hothorn, M.,Mayer, A.
Control of eukaryotic phosphate homeostasis by inositol polyphosphate sensor domains.
Science, 352:986-990, 2016

PubMed Abstract: Phosphorus is a macronutrient taken up by cells as inorganic phosphate (P(i)). How cells sense cellular P(i) levels is poorly characterized. Here, we report that SPX domains--which are found in eukaryotic phosphate transporters, signaling proteins, and inorganic polyphosphate polymerases--provide a basic binding surface for inositol polyphosphate signaling molecules (InsPs), the concentrations of which change in response to P(i) availability. Substitutions of critical binding surface residues impair InsP binding in vitro, inorganic polyphosphate synthesis in yeast, and P(i) transport in Arabidopsis In plants, InsPs trigger the association of SPX proteins with transcription factors to regulate P(i) starvation responses. We propose that InsPs communicate cytosolic P(i) levels to SPX domains and enable them to interact with a multitude of proteins to regulate P(i) uptake, transport, and storage in fungi, plants, and animals.

PubMed: 27080106
DOI: 10.1126/science.aad9858

Experimental method

X-RAY DIFFRACTION (2.75 Å)