3fwi
From Proteopedia
Ferric camphor bound Cytochrome P450cam containing a selenocysteine as the 5th heme ligand, tetragonal crystal form
Structural highlights
FunctionCPXA_PSEPU Involved in a camphor oxidation system. 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 PubMedThe unique monooxygenase activity of cytochrome P450cam has been attributed to coordination of a cysteine thiolate to the heme cofactor. To investigate this interaction, we replaced cysteine with the more electron-donating selenocysteine. Good yields of the selenoenzyme were obtained by bacterial expression of an engineered gene containing the requisite UGA codon for selenocysteine and a simplified yet functional selenocysteine insertion sequence (SECIS). The sulfur-to-selenium substitution subtly modulates the structural, electronic, and catalytic properties of the enzyme. Catalytic activity decreases only 2-fold, whereas substrate oxidation becomes partially uncoupled from electron transfer, implying a more complex role for the axial ligand than generally assumed. Probing the role of the proximal heme ligand in cytochrome P450cam by recombinant incorporation of selenocysteine.,Aldag C, Gromov IA, Garcia-Rubio I, von Koenig K, Schlichting I, Jaun B, Hilvert D Proc Natl Acad Sci U S A. 2009 Mar 17. PMID:19293375[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found See AlsoReferences
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