1HRC

HIGH-RESOLUTION THREE-DIMENSIONAL STRUCTURE OF HORSE HEART CYTOCHROME C


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Observed: 0.179 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

High-resolution three-dimensional structure of horse heart cytochrome c.

Bushnell, G.W.Louie, G.V.Brayer, G.D.

(1990) J Mol Biol 214: 585-595

  • DOI: https://doi.org/10.1016/0022-2836(90)90200-6
  • Primary Citation of Related Structures:  
    1HRC

  • PubMed Abstract: 

    The 1.94 A resolution three-dimensional structure of oxidized horse heart cytochrome c has been elucidated and refined to a final R-factor of 0.17. This has allowed for a detailed assessment of the structural features of this protein, including the presence of secondary structure, hydrogen-bonding patterns and heme geometry. A comprehensive analysis of the structural differences between horse heart cytochrome c and those other eukaryotic cytochromes c for which high-resolution structures are available (yeast iso-1, tuna, rice) has also been completed. Significant conformational differences between these proteins occur in three regions and primarily involve residues 22 to 27, 41 to 43 and 56 to 57. The first of these variable regions is part of a surface beta-loop, whilst the latter two are located together adjacent to the heme group. This study also demonstrates that, in horse cytochrome c, the side-chain of Phe82 is positioned in a co-planar fashion next to the heme in a conformation comparable to that found in other cytochromes c. The positioning of this residue does not therefore appear to be oxidation-state-dependent. In total, five water molecules occupy conserved positions in the structures of horse heart, yeast iso-1, tuna and rice cytochromes c. Three of these are on the surface of the protein, serving to stabilize local polypeptide chain conformations. The remaining two are internally located. One of these mediates a charged interaction between the invariant residue Arg38 and a nearby heme propionate. The other is more centrally buried near the heme iron atom and is hydrogen bonded to the conserved residues Asn52, Tyr67 and Thr78. It is shown that this latter water molecule shifts in a consistent manner upon change in oxidation state if cytochrome c structures from various sources are compared. The conservation of this structural feature and its close proximity to the heme iron atom strongly implicate this internal water molecule as having a functional role in the mechanism of action of cytochrome c.


  • Organizational Affiliation

    Department of Biochemistry, University of British Columbia, Vancouver, Canada.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CYTOCHROME C105Equus caballusMutation(s): 0 
UniProt
Find proteins for P00004 (Equus caballus)
Explore P00004 
Go to UniProtKB:  P00004
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00004
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
HEC
Query on HEC

Download Ideal Coordinates CCD File 
B [auth A]HEME C
C34 H34 Fe N4 O4
HXQIYSLZKNYNMH-LJNAALQVSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Observed: 0.179 
  • Space Group: P 43
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.397α = 90
b = 58.397β = 90
c = 42.091γ = 90
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1994-11-01
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 2.0: 2021-03-10
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Other, Structure summary
  • Version 2.1: 2024-10-23
    Changes: Data collection, Database references, Structure summary