1zzh

Structure of the fully oxidized di-heme cytochrome c peroxidase from R. capsulatus

spinqualitylabelsall models 1zzh, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1zzh is a 4 chain structure with sequence from Rhodobacter capsulatus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.7Å Ligands: CA, HEC, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Cytochrome c peroxidases (CCP) play a key role in cellular detoxification by catalyzing the reduction of hydrogen peroxide to water. The di-heme CCP from Rhodobacter capsulatus is the fastest enzyme (1060 s(-1)), when tested with its physiological cytochrome c substrate, among all di-heme CCPs characterized to date and has, therefore, been an attractive target to investigate structure-function relationships for this family of enzymes. Here, we combine for the first time structural studies with site-directed mutagenesis and spectroscopic studies of the mutant enzymes to investigate the roles of amino acid residues that have previously been suggested to be important for activity. The crystal structure of R. capsulatus at 2.7 Angstroms in the fully oxidized state confirms the overall molecular scaffold seen in other di-heme CCPs but further reveals that a segment of about 10 amino acids near the peroxide binding site is disordered in all four molecules in the asymmetric unit of the crystal. Structural and sequence comparisons with other structurally characterized CCPs suggest that flexibility in this part of the molecular scaffold is an inherent molecular property of the R. capsulatus CCP and of CCPs in general and that it correlates with the levels of activity seen in CCPs characterized, thus, far. Mutagenesis studies support the spin switch model and the roles that Met-118, Glu-117, and Trp-97 play in this model. Our results help to clarify a number of aspects of the debate on structure-function relationships in this family of bacterial CCPs and set the stage for future studies. Structural and mutagenesis studies on the cytochrome c peroxidase from Rhodobacter capsulatus provide new insights into structure-function relationships of bacterial di-heme peroxidases.,De Smet L, Savvides SN, Van Horen E, Pettigrew G, Van Beeumen JJ J Biol Chem. 2006 Feb 17;281(7):4371-9. Epub 2005 Nov 28. PMID:16314410 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome c peroxidase 3D structures

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