6ZFE

Crystal structure of murine S100A9 mutant C80A bound to calcium and zinc


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.305 
  • R-Value Work: 0.268 
  • R-Value Observed: 0.272 

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Literature

Divalent cations influence the dimerization mode of murine S100A9 protein by modulating its disulfide bond pattern.

Signor, L.Paris, T.Mas, C.Picard, A.Lutfalla, G.Boeri Erba, E.Yatime, L.

(2020) J Struct Biol 213: 107689-107689

  • DOI: 10.1016/j.jsb.2020.107689
  • Primary Citation of Related Structures:  
    6ZDY, 6ZFE

  • PubMed Abstract: 
  • S100A9, with its congener S100A8, belongs to the S100 family of calcium-binding proteins found exclusively in vertebrates. These two proteins are major constituents of neutrophils. In response to a pathological condition, they can be released extracellularly and become alarmins that induce both pro- and anti-inflammatory signals, through specific cell surface receptors ...

    S100A9, with its congener S100A8, belongs to the S100 family of calcium-binding proteins found exclusively in vertebrates. These two proteins are major constituents of neutrophils. In response to a pathological condition, they can be released extracellularly and become alarmins that induce both pro- and anti-inflammatory signals, through specific cell surface receptors. They also act as antimicrobial agents, mainly as a S100A8/A9 heterocomplex, through metal sequestration. The mechanisms whereby divalent cations modulate the extracellular functions of S100A8 and S100A9 are still unclear. Importantly, it has been proposed that these ions may affect both the ternary and quaternary structure of these proteins, thereby influencing their physiological properties. In the present study, we report the crystal structures of WT and C80A murine S100A9 (mS100A9), determined at 1.45 and 2.35 Å resolution, respectively, in the presence of calcium and zinc. These structures reveal a canonical homodimeric form for the protein. They also unravel an intramolecular disulfide bridge that stabilizes the C-terminal tail in a rigid conformation, thus shaping a second Zn-binding site per S100A9 protomer. In solution, mS100A9 apparently binds only two zinc ions per homodimer, with an affinity in the micromolar range, and aggregates in the presence of excess zinc. Using mass spectrometry, we demonstrate that mS100A9 can form both non-covalent and covalent homodimers with distinct disulfide bond patterns. Interestingly, calcium and zinc seem to affect differentially the relative proportion of these forms. We discuss how the metal-dependent interconversion between mS100A9 homodimers may explain the versatility of physiological functions attributed to the protein.


    Organizational Affiliation

    LPHI UMR5235, Univ. Montpellier, CNRS, INSERM, F-34095 Montpellier, France. Electronic address: laure.yatime@inserm.fr.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein S100-A9A115Mus musculusMutation(s): 1 
Gene Names: S100a9CagbMrp14
UniProt
Find proteins for P31725 (Mus musculus)
Explore P31725 
Go to UniProtKB:  P31725
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.305 
  • R-Value Work: 0.268 
  • R-Value Observed: 0.272 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.61α = 90
b = 38.8β = 124.75
c = 53.17γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

  • Deposited Date: 2020-06-17 
  • Released Date: 2021-01-13 
  • Deposition Author(s): Paris, T., Yatime, L.

Revision History  (Full details and data files)

  • Version 1.0: 2021-01-13
    Type: Initial release