title: The structure of a retinal-forming carotenoid oxygenase.
abstract: Enzymes that produce retinal and related apocarotenoids constitute a sequence- and thus structure-related family, a member of which was analyzed by x-ray diffraction. This member is an oxygenase and contains an Fe2+-4-His arrangement at the axis of a seven-bladed beta-propeller chain fold covered by a dome formed by six large loops. The Fe2+ is accessible through a long nonpolar tunnel that holds a carotenoid derivative in one of the crystals. On binding, three consecutive double bonds of this carotenoid changed from a straight all-trans to a cranked cis-trans-cis conformation. The remaining trans bond is located at the dioxygen-ligated Fe2+ and cleaved by oxygen.
authors.affiliation: Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, Albertstrasse 21, 79104 Freiburg im Breisgau, Germany.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Kloer
authors.forename: Sandra
authors.initials: S
authors.lastname: Ruch
authors.forename: Salim
authors.initials: S
authors.lastname: Al-Babili
authors.forename: Peter
authors.initials: P
authors.lastname: Beyer
authors.forename: Georg E
authors.initials: GE
authors.lastname: Schulz
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D004926:Escherichia coli; D006801:Humans; D008969:Molecular Sequence Data; D010105:Oxygenases / Q000737:chemistry*; D011487:Protein Conformation; D011994:Recombinant Proteins; D012172:Retinaldehyde / Q000737:chemistry*; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D010105:Oxygenases; D012172:Retinaldehyde