title: Discovery of an L-fucono-1,5-lactonase from cog3618 of the amidohydrolase superfamily.
abstract: A member of the amidohydrolase superfamily, BmulJ_04915 from Burkholderia multivorans, of unknown function was determined to hydrolyze a series of sugar lactones: L-fucono-1,4-lactone, D-arabino-1,4-lactone, L-xylono-1,4-lactone, D-lyxono-1,4-lactone, and L-galactono-1,4-lactone. The highest activity was shown for L-fucono-1,4-lactone with a k(cat) value of 140 s(-1) and a k(cat)/K(m) value of 1.0 × 10(5) M(-1) s(-1) at pH 8.3. The enzymatic product of an adjacent L-fucose dehydrogenase, BmulJ_04919, was shown to be L-fucono-1,5-lactone via nuclear magnetic resonance spectroscopy. L-Fucono-1,5-lactone is unstable and rapidly converts nonenzymatically to L-fucono-1,4-lactone. Because of the chemical instability of L-fucono-1,5-lactone, 4-deoxy-L-fucono-1,5-lactone was enzymatically synthesized from 4-deoxy-L-fucose using L-fucose dehydrogenase. BmulJ_04915 hydrolyzed 4-deoxy-L-fucono-1,5-lactone with a k(cat) value of 990 s(-1) and a k(cat)/K(m) value of 8.0 × 10(6) M(-1) s(-1) at pH 7.1. The protein does not require divalent cations in the active site for catalytic activity. BmulJ_04915 is the second enzyme from cog3618 of the amidohydrolase superfamily that does not require a divalent metal for catalytic activity. BmulJ_04915 is the first enzyme that has been shown to catalyze the hydrolysis of either L-fucono-1,4-lactone or L-fucono-1,5-lactone. The structures of the fuconolactonase and the fucose dehydrogenase were determined by X-ray diffraction methods.
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Merlin Eric
authors.initials: ME
authors.lastname: Hobbs
authors.forename: Matthew
authors.initials: M
authors.lastname: Vetting
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Williams
authors.forename: Tamari
authors.initials: T
authors.lastname: Narindoshvili
authors.forename: Devon M
authors.initials: DM
authors.lastname: Kebodeaux
authors.forename: Brandan
authors.initials: B
authors.lastname: Hillerich
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Seidel
authors.forename: Steven C
authors.initials: SC
authors.lastname: Almo
authors.forename: Frank M
authors.initials: FM
authors.lastname: Raushel
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry* / Q000378:metabolism*; D019117:Burkholderia / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D002237:Carbohydrate Dehydrogenases / Q000737:chemistry / Q000378:metabolism; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D005643:Fucose / Q000378:metabolism*; D006868:Hydrolysis; D007783:Lactones / Q000378:metabolism*; D008958:Models, Molecular; D009249:NADP / Q000378:metabolism; D011487:Protein Conformation; D013379:Substrate Specificity; D013400:Sugar Acids / Q000378:metabolism
chemical_list: D007783:Lactones; D013400:Sugar Acids; C534014:galactono-1,4-lactone; D005643:Fucose; C018458:L-arabino-1,4-lactone; D009249:NADP; D002237:Carbohydrate Dehydrogenases; C020154:L-fucose dehydrogenase; D000581:Amidohydrolases