Ligand-free structure of the GrpU microcompartment shell protein from Clostridiales bacterium 1_7_47FAA

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 

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Identification of a unique fe-s cluster binding site in a glycyl-radical type microcompartment shell protein.

Thompson, M.C.Wheatley, N.M.Jorda, J.Sawaya, M.R.Gidaniyan, S.D.Ahmed, H.Yang, Z.McCarty, K.N.Whitelegge, J.P.Yeates, T.O.

(2014) J Mol Biol 426: 3287-3304

  • DOI: https://doi.org/10.1016/j.jmb.2014.07.018
  • Primary Citation of Related Structures:  
    4OLO, 4OLP

  • PubMed Abstract: 

    Recently, progress has been made toward understanding the functional diversity of bacterial microcompartment (MCP) systems, which serve as protein-based metabolic organelles in diverse microbes. New types of MCPs have been identified, including the glycyl-radical propanediol (Grp) MCP. Within these elaborate protein complexes, BMC-domain shell proteins [bacterial microcompartment (in reference to the shell protein domain)] assemble to form a polyhedral barrier that encapsulates the enzymatic contents of the MCP. Interestingly, the Grp MCP contains a number of shell proteins with unusual sequence features. GrpU is one such shell protein whose amino acid sequence is particularly divergent from other members of the BMC-domain superfamily of proteins that effectively defines all MCPs. Expression, purification, and subsequent characterization of the protein showed, unexpectedly, that it binds an iron-sulfur cluster. We determined X-ray crystal structures of two GrpU orthologs, providing the first structural insight into the homohexameric BMC-domain shell proteins of the Grp system. The X-ray structures of GrpU, both obtained in the apo form, combined with spectroscopic analyses and computational modeling, show that the metal cluster resides in the central pore of the BMC shell protein at a position of broken 6-fold symmetry. The result is a structurally polymorphic iron-sulfur cluster binding site that appears to be unique among metalloproteins studied to date.

  • Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
BMC domain protein
A, B, C, D
109Clostridiales bacterium 1_7_47FAAMutation(s): 0 
Gene Names: CBFG_00659
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 
  • Space Group: P 21 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 130.1α = 90
b = 130.1β = 90
c = 130.1γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-07-30
    Type: Initial release
  • Version 1.1: 2014-08-20
    Changes: Database references
  • Version 1.2: 2014-09-17
    Changes: Database references
  • Version 1.3: 2017-11-22
    Changes: Refinement description
  • Version 1.4: 2024-02-28
    Changes: Data collection, Database references