Crystal structure of an asymmetric dimer of the Geobacillus stearothermophilus SMC hinge domain

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.196 

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Overall Shapes of the SMC-ScpAB Complex Are Determined by Balance between Constraint and Relaxation of Its Structural Parts

Kamada, K.Su'etsugu, M.Takada, H.Miyata, M.Hirano, T.

(2017) Structure 25: 603-616.e4

  • DOI: https://doi.org/10.1016/j.str.2017.02.008
  • Primary Citation of Related Structures:  
    5H66, 5H67, 5H68, 5H69

  • PubMed Abstract: 

    The SMC-ScpAB complex plays a crucial role in chromosome organization and segregation in many bacteria. It is composed of a V-shaped SMC dimer and an ScpAB subcomplex that bridges the two Structural Maintenance of Chromosomes (SMC) head domains. Despite its functional significance, the mechanistic details of SMC-ScpAB remain obscure. Here we provide evidence that ATP-dependent head-head engagement induces a lever movement of the SMC neck region, which might help to separate juxtaposed coiled-coil arms. Binding of the ScpA N-terminal domain (NTD) to the SMC neck region is negatively regulated by the ScpB C-terminal domain. Mutations in the ScpA NTD compromise this regulation and profoundly affect the overall shape of the complex. The SMC hinge domain is structurally relaxed when free from coiled-coil juxtaposition. Taken together, we propose that the structural parts of SMC-ScpAB are subjected to the balance between constraint and relaxation, cooperating to modulate dynamic conformational changes of the whole complex.

  • Organizational Affiliation

    Chromosome Dynamics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. Electronic address: kamadak@riken.jp.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Chromosome partition protein Smc
A, B
261Geobacillus stearothermophilus 10Mutation(s): 0 
Gene Names: smcGT50_02560
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.196 
  • Space Group: P 41
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.144α = 90
b = 77.144β = 90
c = 114.795γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Grants-in-Aid for Science ResearchJapan--

Revision History  (Full details and data files)

  • Version 1.0: 2017-03-15
    Type: Initial release
  • Version 1.1: 2017-04-19
    Changes: Database references
  • Version 1.2: 2020-02-26
    Changes: Data collection
  • Version 1.3: 2023-11-08
    Changes: Data collection, Database references, Refinement description