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1rie
From Proteopedia
| 1rie, resolution 1.50Å () | |||||||||
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| Activity: | Ubiquinol--cytochrome-c reductase, with EC number 1.10.2.2 | ||||||||
| Domains: | Rieske_cytochrome_bc1 | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
STRUCTURE OF A WATER SOLUBLE FRAGMENT OF THE RIESKE IRON-SULFUR PROTEIN OF THE BOVINE HEART MITOCHONDRIAL CYTOCHROME BC1-COMPLEX
BACKGROUND: The 'Rieske' iron-sulfur protein is the primary electron acceptor during hydroquinone oxidation in cytochrome bc complexes. The spectroscopic and electrochemical properties of the 'Rieske' [2Fe-2S] cluster differ significantly from those of other iron-sulfur clusters. A 129-residue water soluble fragment containing the intact [2Fe-2S] cluster was isolated following proteolytic digestion of the bc1 complex and used for structural studies. RESULTS: The structure of the Rieske iron-sulfur fragment containing the reduced [2Fe-2S] cluster has been determined using the multiwavelength anomalous diffraction (MAD) technique and refined at 1.5 A resolution. The fragment has a novel overall fold that includes three sheets of beta strands. The iron atoms of the [2Fe-2S] cluster are coordinated by two cysteine (Fe-1) and two histidine (Fe-2) residues, respectively, with the histidine ligands completely exposed to the solvent. This is in contrast to the four cysteine coordination pattern observed in previously characterised [2Fe-2S] ferredoxins. The cluster-binding fold is formed by two loops connected by a disulfide bridge; these loops superpose with the metal-binding loops of rubredoxins. The environment of the cluster is stabilised by an extensive hydrogen-bond network. CONCLUSIONS: The high-resolution structure supports the proposed coordination pattern involving histidine ligands and provides a basis for a detailed analysis of the spectroscopic and electrochemical properties. As the cluster is located at the tip of the protein, it might come into close contact with cytochrome b. The exposed N epsilon atoms of the histidine ligands of the cluster are readily accessible to quinones and inhibitors within the hydroquinone oxidation (QP) pocket of the bc1 complex and may undergo redox-dependent protonation/deprotonation.
Structure of a water soluble fragment of the 'Rieske' iron-sulfur protein of the bovine heart mitochondrial cytochrome bc1 complex determined by MAD phasing at 1.5 A resolution., Iwata S, Saynovits M, Link TA, Michel H, Structure. 1996 May 15;4(5):567-79. PMID:8736555
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1RIE is a 1 chain structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
- Iwata S, Saynovits M, Link TA, Michel H. Structure of a water soluble fragment of the 'Rieske' iron-sulfur protein of the bovine heart mitochondrial cytochrome bc1 complex determined by MAD phasing at 1.5 A resolution. Structure. 1996 May 15;4(5):567-79. PMID:8736555
Page seeded by OCA on Mon Feb 16 10:29:16 2009
