title: Biosynthesis of a 3,6-dideoxyhexose: crystallization and X-ray diffraction of CDP-6-deoxy-L-threo-D-glycero-4-hexulose-3-dehydrase (E1) for ascarylose biosynthesis.
abstract: CDP-6-deoxy-L-threo-D-glycero-4-hexulose-3-dehydrase (E1), along with its reductase (E3), catalyzes the unusual C-3 deoxygenation of CDP-6-deoxy-L-threo-D-glycero-4-hexulose to form CDP-3,6-dideoxy-L-threo-D-glycero-4-hexulose in CDP-ascarylose biosynthesis [Chen et al. (1996), Biochemistry, 35, 16412-16420]. This dimeric [2Fe-2S] protein, cloned from the bacteria Yersinia pseudotuberculosis, is currently the only known example of an enzyme that uses a vitamin B6-derived pyridoxamine 5'-phosphate (PMP) cofactor to carry out one-electron chemistry [Agnihotri & Liu (2001), Bioorg. Chem. 29, 234-257]. It also exhibits a [2Fe-2S] cluster-binding motif (C-X57-C-X1-C-X7-C) which has not been observed previously [Agnihotri et al. (2004), Biochemistry, 43, 14265-14274] The recombinant 97.7 kDa dimer was crystallized in the trigonal space group P3(2), with unit-cell parameters a = b = 97.37, c = 142.2 A, alpha = beta = 90, gamma = 120 degrees. A data set has been collected to 1.9 A resolution. A full MAD data set was also collected at the iron absorption edge that diffracted to 2.0 A.
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Smith
authors.forename: Ava
authors.initials: A
authors.lastname: Lin
authors.forename: Pin-hui
authors.initials: PH
authors.lastname: Szu
authors.forename: Hung-wen
authors.initials: HW
authors.lastname: Liu
authors.forename: Shiou-Chuan
authors.initials: SC
authors.lastname: Tsai
mesh_terms: D003460:Crystallization / Q000379:methods; D018360:Crystallography, X-Ray; D006601:Hexoses / Q000096:biosynthesis*; D006836:Hydro-Lyases / Q000096:biosynthesis / Q000737:chemistry*; D011994:Recombinant Proteins / Q000096:biosynthesis; D015011:Yersinia pseudotuberculosis / Q000201:enzymology
chemical_list: D006601:Hexoses; D011994:Recombinant Proteins; C009616:tyvelose; C073141:CDP-4-keto-6-deoxy-D-glucose-3-dehydrase; D006836:Hydro-Lyases