title: Functional characterization of aconitase X as a cis-3-hydroxy-L-proline dehydratase.
abstract: In the aconitase superfamily, which includes the archetypical aconitase, homoaconitase, and isopropylmalate isomerase, only aconitase X is not functionally annotated. The corresponding gene (LhpI) was often located within the bacterial gene cluster involved in L-hydroxyproline metabolism. Screening of a library of (hydroxy)proline analogues revealed that this protein catalyzes the dehydration of cis-3-hydroxy-L-proline to Δ1-pyrroline-2-carboxylate. Furthermore, electron paramagnetic resonance and site-directed mutagenic analyses suggests the presence of a mononuclear Fe(III) center, which may be coordinated with one glutamate and two cysteine residues. These properties were significantly different from those of other aconitase members, which catalyze the isomerization of α- to β-hydroxy acids, and have a [4Fe-4S] cluster-binding site composed of three cysteine residues. Bacteria with the LhpI gene could degrade cis-3-hydroxy-L-proline as the sole carbon source, and LhpI transcription was up-regulated not only by cis-3-hydroxy-L-proline, but also by several isomeric 3- and 4-hydroxyprolines.
authors.affiliation: Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.|Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.|Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
authors.forename: Seiya
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Department of Bio-molecular Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Tajima
authors.affiliation: Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Faculty of Food and Nutritional Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan.
authors.forename: Fumiyasu
authors.initials: F
authors.lastname: Fukumori
authors.affiliation: Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Hara
authors.affiliation: Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
authors.forename: Rio
authors.initials: R
authors.lastname: Fukuda
authors.affiliation: Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
authors.forename: Mao
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.|Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Kuniki
authors.initials: K
authors.lastname: Kino
authors.affiliation: Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.|Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000154:Aconitate Hydratase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D020134:Catalytic Domain; D006836:Hydro-Lyases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006909:Hydroxyproline / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D007506:Iron-Sulfur Proteins; D006836:Hydro-Lyases; D000154:Aconitate Hydratase; D006909:Hydroxyproline