The structure of a retinal-forming carotenoid oxygenase.
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.
Kloer
Daniel P
DP
Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, Albertstrasse 21, 79104 Freiburg im Breisgau, Germany.
Ruch
Sandra
S
Al-Babili
Salim
S
Beyer
Peter
P
Schulz
Georg E
GE
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
D011994:Recombinant Proteins; D010105:Oxygenases; D012172:Retinaldehyde