Macromolecule Content

• Total Structure Weight: 9.19 kDa 
• Atom Count: 634 
• Residue Count: 68 
• Unique protein chains: 1

1LM2

NMR structural characterization of the reduction of chromium(VI) to chromium(III) by cytochrome c7

• DOI: 10.2210/pdb1LM2/pdb

• Classification: ELECTRON TRANSPORT
• Organism(s): Desulfuromonas acetoxidans
• Mutation(s): No 


• Deposited: 2002-04-30 Released: 2002-07-31 
• Deposition Author(s): Assfalg, M., Bertini, I., Bruschi, M., Michel, C., Turano, P.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 500 
• Conformers Submitted: 35 
• Selection Criteria: structures with best target function 

Literature

The metal reductase activity of some multiheme cytochromes c: NMR structural characterization of the reduction of chromium(VI) to chromium(III) by cytochrome c(7).

Assfalg, M., Bertini, I., Bruschi, M., Michel, C., Turano, P.

(2002) Proc Natl Acad Sci U S A 99: 9750-9754

• PubMed: 12119407 
• DOI: 10.1073/pnas.152290999
• Primary Citation of Related Structures:  
  1LM2


• PubMed Abstract: 
  

The redox reaction between CrO(4)(2-) and the fully reduced three-heme cytochrome c(7) from Desulfuromonas acetoxidans to give chromium(III) and the fully oxidized protein has been followed by NMR spectroscopy. The hyperfine coupling between the oxidized protein protons and chromium(III), which remains bound to the protein, gives rise to line-broadening effects on the NMR resonances that can be transformed into proton-metal distance restraints. Structure calculations based on these unconventional constraints allowed us to demonstrate that chromium(III) binds at a unique site and to locate it on the protein surface. The metal ion is located 7.9 +/- 0.4 A from the iron of heme IV, 16.3 +/- 0.7 A from the iron of heme III, and 22.5 +/- 0.5 A from the iron of heme I. Shift changes caused by the presence of unreactive MoO(4)(2-), a CrO(4)(2-) analogue, indicate the involvement of the same protein area in the anion binding. The titration of the oxidation of cytochrome c(7) shows a detailed mechanism of action. The presence of a specific binding site supports the hypothesis of the biological role of this cytochrome as a metal reductase.

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Organizational Affiliation: 

Magnetic Resonance Center and Department of Chemistry, University of Florence, Via Luigi Sacconi, 6, 50019 Sesto Fiorentino (Florence), Italy.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
cytochrome c7	A	68	Desulfuromonas acetoxidans	Mutation(s): 0  Gene Names: cyd
Find proteins for P00137 (Desulfuromonas acetoxidans) Explore P00137  Go to UniProtKB:  P00137

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HEC	A	HEME C C34 H34 Fe N4 O4 HXQIYSLZKNYNMH-LJNAALQVSA-N
CR	A	CHROMIUM ION Cr BFGKITSFLPAWGI-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 500 
• Conformers Submitted: 35 
• Selection Criteria: structures with best target function 
• OLDERADO: 1LM2 Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2002-04-30 
• Released Date: 2002-07-31 
Deposition Author(s): Assfalg, M., Bertini, I., Bruschi, M., Michel, C., Turano, P.

Revision History 

• Version 1.0: 2002-07-31
  Type: Initial release
  
• Version 1.1: 2008-04-28
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance