7JMB

Crystal structure of Nitrogenase iron-molybdenum cofactor biosynthesis enzyme NifB from Methanothermobacter thermautotrophicus with three Fe4S4 clusters


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.314 
  • R-Value Work: 0.262 
  • R-Value Observed: 0.268 

Starting Model: experimental
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This is version 1.4 of the entry. See complete history


Literature

X-Ray Crystallographic Analysis of NifB with a Full Complement of Clusters: Structural Insights into the Radical SAM-Dependent Carbide Insertion During Nitrogenase Cofactor Assembly.

Kang, W.Rettberg, L.A.Stiebritz, M.T.Jasniewski, A.J.Tanifuji, K.Lee, C.C.Ribbe, M.W.Hu, Y.

(2021) Angew Chem Int Ed Engl 60: 2364-2370

  • DOI: https://doi.org/10.1002/anie.202011367
  • Primary Citation of Related Structures:  
    7JMA, 7JMB

  • PubMed Abstract: 

    NifB is an essential radical SAM enzyme required for the assembly of an 8Fe core of the nitrogenase cofactor. Herein, we report the X-ray crystal structures of Methanobacterium thermoautotrophicum NifB without (apo MtNifB) and with (holo MtNifB) a full complement of three [Fe 4 S 4 ] clusters. Both apo and holo MtNifB contain a partial TIM barrel core, but unlike apo MtNifB, holo MtNifB is fully assembled and competent in cofactor biosynthesis. The radical SAM (RS)-cluster is coordinated by three Cys, and the adjacent K1- and K2-clusters, representing the precursor to an 8Fe cofactor core, are each coordinated by one His and two Cys. Prediction of substrate channels, combined with in silico docking of SAM in holo MtNifB, suggests the binding of SAM between the RS- and K2-clusters and putative paths for entry of SAM and exit of products of SAM cleavage, thereby providing important mechanistic insights into the radical SAM-dependent carbide insertion concomitant with cofactor core formation.


  • Organizational Affiliation

    Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, 92697-3900, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Nitrogenase iron-molybdenum cofactor biosynthesis protein NifB
A, B
290Methanothermobacter thermautotrophicusMutation(s): 0 
UniProt
Find proteins for O27899 (Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H))
Explore O27899 
Go to UniProtKB:  O27899
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO27899
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 121.87α = 90
b = 77.64β = 128.85
c = 90.8γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
iMOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM67626
Department of Energy (DOE, United States)United StatesDE-SC0016510

Revision History  (Full details and data files)

  • Version 1.0: 2020-10-28
    Type: Initial release
  • Version 1.1: 2020-12-09
    Changes: Database references
  • Version 1.2: 2021-01-20
    Changes: Database references
  • Version 1.3: 2021-02-03
    Changes: Database references
  • Version 1.4: 2023-10-18
    Changes: Data collection, Database references, Refinement description