Bacillus subtilis manganese transport regulator (MNTR) bound to manganese, AB conformation, pH 6.5

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.237 

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Structural Basis for the Metal-Selective Activation of the Manganese Transport Regulator of Bacillus subtilis.

Kliegman, J.I.Griner, S.L.Helmann, J.D.Brennan, R.G.Glasfeld, A.

(2006) Biochemistry 45: 3493-3505

  • DOI: https://doi.org/10.1021/bi0524215
  • Primary Citation of Related Structures:  
    2EV0, 2EV5, 2EV6, 2F5C, 2F5D, 2F5E, 2F5F

  • PubMed Abstract: 

    The manganese transport regulator (MntR) of Bacillus subtilis is activated by Mn(2+) to repress transcription of genes encoding transporters involved in the uptake of manganese. MntR is also strongly activated by cadmium, both in vivo and in vitro, but it is poorly activated by other metal cations, including calcium and zinc. The previously published MntR.Mn(2+) structure revealed a binuclear complex of manganese ions with a metal-metal separation of 3.3 A (herein designated the AB conformer). Analysis of four additional crystal forms of MntR.Mn(2+) reveals that the AB conformer is only observed in monoclinic crystals at 100 K, suggesting that this conformation may be stabilized by crystal packing forces. In contrast, monoclinic crystals analyzed at room temperature (at either pH 6.5 or pH 8.5), and a second hexagonal crystal form (analyzed at 100 K), all reveal the shift of one manganese ion by 2.5 A, thereby leading to a newly identified conformation (the AC conformer) with an internuclear distance of 4.4 A. Significantly, the cadmium and calcium complexes of MntR also contain binuclear complexes with a 4.4 A internuclear separation. In contrast, the zinc complex of MntR contains only one metal ion per subunit, in the A site. Isothermal titration calorimetry confirms the stoichiometry of Mn(2+), Cd(2+), and Zn(2+) binding to MntR. We propose that the specificity of MntR activation is tied to productive binding of metal ions at two sites; the A site appears to act as a selectivity filter, determining whether the B or C site will be occupied and thereby fully activate MntR.

  • Organizational Affiliation

    Department of Chemistry, Reed College, Portland, Oregon 97202, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Transcriptional regulator mntR
A, B
142Bacillus subtilisMutation(s): 0 
Gene Names: mntR
Find proteins for P54512 (Bacillus subtilis (strain 168))
Explore P54512 
Go to UniProtKB:  P54512
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP54512
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.237 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.4α = 90
b = 46.01β = 92.93
c = 74.36γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-03-07
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description