8DBY

CryoEM structure of anaerobically prepared nitrogenase MoFe-protein on ultrathin carbon


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.26 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Anaerobic cryoEM protocols for air-sensitive nitrogenase proteins.

Warmack, R.A.Wenke, B.B.Spatzal, T.Rees, D.C.

(2024) Nat Protoc 

  • DOI: https://doi.org/10.1038/s41596-024-00973-5
  • Primary Citation of Related Structures:  
    8DBY, 8DFC, 8DFD, 8TC3

  • PubMed Abstract: 

    Single-particle cryo-electron microscopy (cryoEM) provides an attractive avenue for advancing our atomic resolution understanding of materials, molecules and living systems. However, the vast majority of published cryoEM methodologies focus on the characterization of aerobically purified samples. Air-sensitive enzymes and microorganisms represent important yet understudied systems in structural biology. We have recently demonstrated the success of an anaerobic single-particle cryoEM workflow applied to the air-sensitive nitrogenase enzymes. In this protocol, we detail the use of Schlenk lines and anaerobic chambers to prepare samples, including a protein tag for monitoring sample exposure to oxygen in air. We describe how to use a plunge freezing apparatus inside of a soft-sided vinyl chamber of the type we routinely use for anaerobic biochemistry and crystallography of oxygen-sensitive proteins. Manual control of the airlock allows for introduction of liquid cryogens into the tent. A custom vacuum port provides slow, continuous evacuation of the tent atmosphere to avoid accumulation of flammable vapors within the enclosed chamber. These methods allowed us to obtain high-resolution structures of both nitrogenase proteins using single-particle cryoEM. The procedures involved can be generally subdivided into a 4 d anaerobic sample generation procedure, and a 1 d anaerobic cryoEM sample preparation step, followed by conventional cryoEM imaging and processing steps. As nitrogen is a substrate for nitrogenase, the Schlenk lines and anaerobic chambers described in this procedure are operated under an argon atmosphere; however, the system and these procedures are compatible with other controlled gas environments.


  • Organizational Affiliation

    Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA. rwarmack@caltech.edu.


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
Expand
  • 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): 0 
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
Expand
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ICS
Query on ICS

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

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

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

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.26 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM045162
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM143836-01
Howard Hughes Medical Institute (HHMI)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2023-06-21
    Type: Initial release
  • Version 1.1: 2024-04-17
    Changes: Data collection, Database references