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spinqualitylabelsall models 1m57, resolution 3.0Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Structure of cytochrome c oxidase from Rhodobacter sphaeroides (EQ(I-286) mutant))

Overview

The structure of cytochrome c oxidase from Rhodobacter sphaeroides has been solved at 2.3/2.8A (anisotropic resolution). This high-resolution structure revealed atomic details of a bacterial terminal oxidase including water molecule positions and a potential oxygen pathway, which has not been reported in other oxidase structures. A comparative study of the wild-type and the EQ(I-286) mutant enzyme revealed structural rearrangements around E(I-286) that could be crucial for proton transfer in this enzyme. In the structure of the mutant enzyme, EQ(I-286), which cannot transfer protons during oxygen reduction, the side-chain of Q(I-286) does not have the hydrogen bond to the carbonyl oxygen of M(I-107) that is seen in the wild-type structure. Furthermore, the Q(I-286) mutant has a different arrangement of water molecules and residues in the vicinity of the Q side-chain. These differences between the structures could reflect conformational changes that take place upon deprotonation of E(I-286) during turnover of the wild-type enzyme, which could be part of the proton-pumping machinery of the enzyme.

About this Structure

1M57 is a Protein complex structure of sequences from Rhodobacter sphaeroides with , , , and as ligands. Active as Cytochrome-c oxidase, with EC number 1.9.3.1 Full crystallographic information is available from OCA.

Reference

The X-ray crystal structures of wild-type and EQ(I-286) mutant cytochrome c oxidases from Rhodobacter sphaeroides., Svensson-Ek M, Abramson J, Larsson G, Tornroth S, Brzezinski P, Iwata S, J Mol Biol. 2002 Aug 9;321(2):329-39. PMID:12144789

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