2mhm

Solution structure of cytochrome c Y67H

spinqualitylabelsall models 2mhm, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2mhm is a 1 chain structure. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: HEC Resources: FirstGlance, OCA, RCSB, PDBsum Function [CYC1_YEAST] Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. Publication Abstract from PubMed The catalytic activity of cytochrome c (cyt c) to peroxidize cardiolipin to its oxidized form is required for the release of pro-apoptotic factors from mitochondria, and for execution of the subsequent apoptotic steps. However, the structural basis for this peroxidation reaction remains unclear. In this paper, we determined the three-dimensional NMR solution structure of yeast cyt c Y67H variant with high peroxidase activity, which is almost similar to that of its native form. The structure reveals that the hydrogen bond between Met80 and residue 67 is disrupted. This change destabilizes the sixth coordination bond between heme Fe(3+) ion and Met80 sulfur atom in the Y67H variant, and further makes it more easily be broken at low pH conditions. The steady-state studies indicate that the Y67H variant has the highest peroxidase activities when pH condition is between 4.0 and 5.2. Finally, a mechanism is suggested for the peroxidation of cardiolipin catalyzed by the Y67H variant, where the residue His67 acts as a distal histidine, its protonation facilitates O-O bond cleavage of H2O2 by functioning as an acidic catalyst. Structural basis for cytochrome c Y67H mutant to function as a peroxidase.,Lan W, Wang Z, Yang Z, Ying T, Zhang X, Tan X, Liu M, Cao C, Huang ZX PLoS One. 2014 Sep 11;9(9):e107305. doi: 10.1371/journal.pone.0107305., eCollection 2014. PMID:25210769 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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