3hb6

Inactive mutant H54F of Proteus mirabilis catalase

spinqualitylabelsall models 3hb6, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3hb6 is a 1 chain structure with sequence from Proteus mirabilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.3Å Ligands: GOL, HEM, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CATA_PROMI Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide. 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 BACKGROUND: Heme oxidative degradation has been extensively investigated in peroxidases but not in catalases. The verdoheme formation, a product of heme oxidation which inactivates the enzyme, was studied in Proteus mirabilis catalase. METHODS: The verdoheme was generated by adding peracetic acid and analyzed by mass spectrometry and spectrophotometry. RESULTS: Kinetics follow-up of different catalase reactional intermediates shows that i) the formation of compound I always precedes that of verdoheme, ii) compound III is never observed, iii) the rate of compound II decomposition is not compatible with that of verdoheme formation, and iv) dithiothreitol prevents the verdoheme formation but not that of compound II, whereas NADPH prevents both of them. The formation of verdoheme is strongly inhibited by EDTA but not increased by Fe3+ or Cu2+ salts. The generation of verdoheme is facilitated by the presence of protein radicals as observed in the F194Y mutated catalase. The inability of the inactive variant (H54F) to form verdoheme, indicates that the heme oxidation is fully associated to the enzyme catalysis. CONCLUSION: These data, taken together, strongly suggest that the verdoheme formation pathway originates from compound I rather than from compound II. GENERAL SIGNIFICANCE: The autocatalytic verdoheme formation is likely to occur in vivo. Verdoheme formation in Proteus mirabilis catalase.,Andreoletti P, Mouesca JM, Gouet P, Jaquinod M, Capeillere-Blandin C, Jouve HM Biochim Biophys Acta. 2009 Aug;1790(8):741-53. Epub 2009 Apr 24. PMID:19394409 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Catalase 3D structures

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