Biological Assembly 1  

 3D View: Structure | 1D-3D View | Validation Report | Predict Membrane 

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 22.77 kDa 
• Atom Count: 1479 
• Modelled Residue Count: 192 
• Deposited Residue Count: 208 
• Unique protein chains: 1

2N4X

Structure of the Transmembrane Electron Transporter CcdA

• PDB DOI: 10.2210/pdb2N4X/pdb
• BMRB: 25685

• Classification: MEMBRANE PROTEIN
• Organism(s): Archaeoglobus fulgidus DSM 4304
• Expression System: Escherichia coli
• Mutation(s): Yes 
• Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc


• Deposited: 2015-07-01 Released: 2016-05-18 
• Deposition Author(s): Chou, J.J., Williamson, J.A.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 75 
• Conformers Submitted: 15 
• Selection Criteria: structures with the lowest energy 

Literature

Structure and multistate function of the transmembrane electron transporter CcdA.

Williamson, J.A., Cho, S.H., Ye, J., Collet, J.F., Beckwith, J.R., Chou, J.J.

(2015) Nat Struct Mol Biol 22: 809-814

• PubMed: 26389738 
• DOI: 10.1038/nsmb.3099
• Primary Citation of Related Structures:  
  2N4X


• PubMed Abstract: 
  

The mechanism by which transmembrane reductases use a single pair of cysteine residues to relay electrons between protein substrates across biological membranes is a long-standing mystery in thiol-redox biochemistry. Here we show the NMR structure of a reduced-state mimic of archaeal CcdA, a protein that transfers electrons across the inner membrane, by using a redox-active NMR sample. The two cysteine positions in CcdA are separated by 20 Å. Whereas one is accessible to the cytoplasm, the other resides in the protein core, thus implying that conformational exchange is required for periplasmic accessibility. In vivo mixed disulfide-trapping experiments validated the functional positioning of the cysteines, and in vitro accessibility results confirmed conformational exchange. Our NMR and functional data together show the existence of multiple conformational states and suggest a four-state model for relaying electrons from cytosolic to periplasmic redox substrates.

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Organizational Affiliation: 

Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cytochrome C-type biogenesis protein (CcdA)	A	208	Archaeoglobus fulgidus DSM 4304	Mutation(s): 2  Gene Names: AF_1057 Membrane Entity: Yes
UniProt
Find proteins for O29205 (Archaeoglobus fulgidus (strain ATCC 49558 / DSM 4304 / JCM 9628 / NBRC 100126 / VC-16)) Explore O29205  Go to UniProtKB:  O29205

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 75 
• Conformers Submitted: 15 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 2N4X Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2015-07-01 
• Released Date: 2016-05-18 
Deposition Author(s): Chou, J.J., Williamson, J.A.

Revision History  

• Version 1.0: 2016-05-18
  Type: Initial release