3BXU

PpcB, A Cytochrome c7 from Geobacter sulfurreducens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.186 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.164 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural insights into the modulation of the redox properties of two Geobacter sulfurreducens homologous triheme cytochromes.

Morgado, L.Bruix, M.Orshonsky, V.Londer, Y.Y.Duke, N.E.Yang, X.Pokkuluri, P.R.Schiffer, M.Salgueiro, C.A.

(2008) Biochim Biophys Acta 1777: 1157-1165

  • DOI: 10.1016/j.bbabio.2008.04.043
  • Primary Citation of Related Structures:  
    3BXU

  • PubMed Abstract: 
  • The redox properties of a periplasmic triheme cytochrome, PpcB from Geobacter sulfurreducens, were studied by NMR and visible spectroscopy. The structure of PpcB was determined by X-ray diffraction. PpcB is homologous to PpcA (77% sequence identity), whi ...

    The redox properties of a periplasmic triheme cytochrome, PpcB from Geobacter sulfurreducens, were studied by NMR and visible spectroscopy. The structure of PpcB was determined by X-ray diffraction. PpcB is homologous to PpcA (77% sequence identity), which mediates cytoplasmic electron transfer to extracellular acceptors and is crucial in the bioenergetic metabolism of Geobacter spp. The heme core structure of PpcB in solution, probed by 2D-NMR, was compared to that of PpcA. The results showed that the heme core structures of PpcB and PpcA in solution are similar, in contrast to their crystal structures where the heme cores of the two proteins differ from each other. NMR redox titrations were carried out for both proteins and the order of oxidation of the heme groups was determined. The microscopic properties of PpcB and PpcA redox centers showed important differences: (i) the order in which hemes become oxidized is III-I-IV for PpcB, as opposed to I-IV-III for PpcA; (ii) the redox-Bohr effect is also different in the two proteins. The different redox features observed between PpcB and PpcA suggest that each protein uniquely modulates the properties of their co-factors to assure effectiveness in their respective metabolic pathways. The origins of the observed differences are discussed.


    Organizational Affiliation

    Requimte-CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus Caparica, 2829-516 Caparica, Portugal.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome c3 AB71Geobacter sulfurreducensMutation(s): 0 
Gene Names: cyd-1
Find proteins for Q74G83 (Geobacter sulfurreducens (strain ATCC 51573 / DSM 12127 / PCA))
Explore Q74G83 
Go to UniProtKB:  Q74G83
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.186 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.164 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.2α = 90
b = 47.5β = 90
c = 88.9γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-07-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance