Discovery of an L-fucono-1,5-lactonase from cog3618 of the amidohydrolase superfamily. uri icon

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.

published proceedings

  • Biochemistry

author list (cited authors)

  • Hobbs, M. E., Vetting, M., Williams, H. J., Narindoshvili, T., Kebodeaux, D. M., Hillerich, B., ... Raushel, F. M.

citation count

  • 24

complete list of authors

  • Hobbs, Merlin Eric||Vetting, Matthew||Williams, Howard J||Narindoshvili, Tamari||Kebodeaux, Devon M||Hillerich, Brandan||Seidel, Ronald D||Almo, Steven C||Raushel, Frank M

publication date

  • January 2013