6O7L

Nitrogenase MoFeP mutant S188A from Azotobacter vinelandii in the dithionite reduced state after redox cycling

  • Classification: OXIDOREDUCTASE
  • Organism(s): Azotobacter vinelandii
  • Mutation(s): Yes 

  • Deposited: 2019-03-08 Released: 2019-06-19 
  • Deposition Author(s): Rutledge, H.L., Tezcan, F.A.
  • Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), Other private

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.26 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.213 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Redox-Dependent Metastability of the Nitrogenase P-Cluster.

Rutledge, H.L.Rittle, J.Williamson, L.M.Xu, W.A.Gagnon, D.M.Tezcan, F.A.

(2019) J Am Chem Soc 141: 10091-10098

  • DOI: https://doi.org/10.1021/jacs.9b04555
  • Primary Citation of Related Structures:  
    6O7L, 6O7M, 6O7N, 6O7O, 6O7P, 6O7Q, 6O7R, 6O7S

  • PubMed Abstract: 

    Molybdenum nitrogenase catalyzes the reduction of dinitrogen into ammonia, which requires the coordinated transfer of eight electrons to the active site cofactor (FeMoco) through the intermediacy of an [8Fe-7S] cluster (P-cluster), both housed in the molybdenum-iron protein (MoFeP). Previous studies on MoFeP from two different organisms, Azotobacter vinelandii ( Av) and Gluconacetobacter diazotrophicus ( Gd), have established that the P-cluster is conformationally flexible and can undergo substantial structural changes upon two-electron oxidation to the P OX state, whereby a backbone amidate and an oxygenic residue (Ser or Tyr) ligate to two of the cluster's Fe centers. This redox-dependent change in coordination has been implicated in the conformationally gated electron transfer in nitrogenase. Here, we have investigated the role of the oxygenic ligand in Av MoFeP, which natively contains a Ser ligand (βSer188) to the P-cluster. Three variants were generated in which (1) the oxygenic ligand was eliminated (βSer188Ala), (2) the P-cluster environment was converted to the one in Gd MoFeP (βPhe99Tyr/βSer188Ala), and (3) two oxygenic ligands were simultaneously included (βPhe99Tyr). Our studies have revealed that the P-cluster can become compositionally labile upon oxidation and reversibly lose one or two Fe centers in the absence of the oxygenic ligand, while still retaining wild-type-like dinitrogen reduction activity. Our findings also suggest that Av and Gd MoFePs evolved with specific preferences for Ser and Tyr ligands, respectively, and that the structural control of these ligands must extend beyond the primary and secondary coordination spheres of the P-cluster. The P-cluster adds to the increasing number of examples of inherently labile Fe-S clusters whose compositional instability may be an obligatory feature to enable redox-linked conformational changes to facilitate multielectron redox reactions.


  • Organizational Affiliation

    Department of Chemistry and Biochemistry , University of California, San Diego , 9500 Gilman Drive , La Jolla , California 92093-0356 , United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Nitrogenase molybdenum-iron protein alpha chain
A, C
492Azotobacter vinelandiiMutation(s): 0 
EC: 1.18.6.1
UniProt
Find proteins for P07328 (Azotobacter vinelandii)
Explore P07328 
Go to UniProtKB:  P07328
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07328
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Nitrogenase molybdenum-iron protein beta chain
B, D
523Azotobacter vinelandiiMutation(s): 1 
EC: 1.18.6.1
UniProt
Find proteins for P07329 (Azotobacter vinelandii)
Explore P07329 
Go to UniProtKB:  P07329
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07329
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ICS
Query on ICS

Download Ideal Coordinates CCD File 
F [auth A],
K [auth C]
iron-sulfur-molybdenum cluster with interstitial carbon
C Fe7 Mo S9
DDQFAOMIVKLFON-UHFFFAOYSA-N
CLF
Query on CLF

Download Ideal Coordinates CCD File 
G [auth B],
L [auth D]
FE(8)-S(7) CLUSTER
Fe8 S7
JKVMXLBGZBULKV-UHFFFAOYSA-N
HCA
Query on HCA

Download Ideal Coordinates CCD File 
E [auth A],
J [auth C]
3-HYDROXY-3-CARBOXY-ADIPIC ACID
C7 H10 O7
XKJVEVRQMLKSMO-SSDOTTSWSA-N
FE
Query on FE

Download Ideal Coordinates CCD File 
H [auth B],
I [auth B]
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.26 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.213 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 80.562α = 90
b = 131.029β = 110.85
c = 107.616γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM099813
Other privateUnited StatesHerman Frasch Foundation 735-HF12

Revision History  (Full details and data files)

  • Version 1.0: 2019-06-19
    Type: Initial release
  • Version 1.1: 2019-07-10
    Changes: Data collection, Database references
  • Version 1.2: 2020-01-01
    Changes: Author supporting evidence
  • Version 1.3: 2023-10-11
    Changes: Data collection, Database references, Derived calculations, Refinement description