3ISE

Structure of mineralized Bfrb (double soak) from Pseudomonas aeruginosa to 2.8A Resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Studies of Bacterioferritin B from Pseudomonas aeruginosa Suggest a Gating Mechanism for Iron Uptake via the Ferroxidase Center

Weeratunga, S.K.Lovell, S.Yao, H.Battaile, K.P.Fischer, C.J.Gee, C.E.Rivera, M.

(2010) Biochemistry 49: 1160-1175

  • DOI: 10.1021/bi9015204
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The structure of recombinant Pseudomonas aeruginosa bacterioferritin B (Pa BfrB) has been determined from crystals grown from protein devoid of core mineral iron (as-isolated) and from protein mineralized with approximately 600 iron atoms (mineralize ...

    The structure of recombinant Pseudomonas aeruginosa bacterioferritin B (Pa BfrB) has been determined from crystals grown from protein devoid of core mineral iron (as-isolated) and from protein mineralized with approximately 600 iron atoms (mineralized). Structures were also obtained from crystals grown from mineralized BfrB after they had been soaked in an FeSO(4) solution (Fe soak) and in separate experiments after they had been soaked in an FeSO(4) solution followed by a soak in a crystallization solution (double soak). Although the structures consist of a typical bacterioferritin fold comprised of a nearly spherical 24-mer assembly that binds 12 heme molecules, comparison of microenvironments observed in the distinct structures provided interesting insights. The ferroxidase center in the as-isolated, mineralized, and double-soak structures is empty. The ferroxidase ligands (except His130) are poised to bind iron with minimal conformational changes. The His130 side chain, on the other hand, must rotate toward the ferroxidase center to coordinate iron. In comparison, the structure obtained from crystals soaked in an FeSO(4) solution displays a fully occupied ferroxidase center and iron bound to the internal, Fe((in)), and external, Fe((out)), surfaces of Pa BfrB. The conformation of His130 in this structure is rotated toward the ferroxidase center and coordinates an iron ion. The structures also revealed a pore on the surface of Pa BfrB that likely serves as a port of entry for Fe(2+) to the ferroxidase center. On its opposite end, the pore is capped by the side chain of His130 when it adopts its "gate-closed" conformation that enables coordination to a ferroxidase iron. A change to its "gate-open", noncoordinative conformation creates a path for the translocation of iron from the ferroxidase center to the interior cavity. These structural observations, together with findings obtained from iron incorporation measurements in solution, suggest that the ferroxidase pore is the dominant entry route for the uptake of iron by Pa BfrB. These findings, which are clearly distinct from those made with Escherichia coli Bfr [Crow, A. C., Lawson, T. L., Lewin, A., Moore, G. R., and Le Brun, N. E. (2009) J. Am. Chem. Soc. 131, 6808-6813], indicate that not all bacterioferritins operate in the same manner.


    Organizational Affiliation

    Ralph N. Adams Institute for Bioanalytical Chemistry and Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Drive, Room 220 E, Lawrence, Kansas 66047, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Bacterioferritin
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X
158Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)Mutation(s): 0 
Gene Names: bfrB
EC: 1.16.3.1
Find proteins for Q9HY79 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Go to UniProtKB:  Q9HY79
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A, B, C, G, N, V
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM

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Download CCD File 
B, D, E, H, J, L, M, P, R, S, U, W
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A, B, C, D, E, F, G, I, K, L, M, N, P, Q, T, U, V, W
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.195 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 125.712α = 90.00
b = 203.206β = 90.00
c = 207.865γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
d*TREKdata scaling
PDB_EXTRACTdata extraction
SCALEPACKdata scaling
d*TREKdata reduction
PHASERphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-02-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description