Neutron diffraction studies towards deciphering the protonation state of catalytic residues in the bacterial KDN9P phosphatase

作者：Bryan Tyrel; Gonzalez Javier M; Bacik John P; DeNunzio Nicholas J; Unkefer Clifford J; Schrader Tobias E; Ostermann Andreas; Dunaway Mariano Debra; Allen Karen N; Fisher S Zoe^*

来源：Acta Crystallographica Section F-Structural Biology and Crystallization Communications, 2013, 69(9): 1015-1019.

DOI：10.1107/S1744309113021386

The enzyme 2-keto-3-deoxy-9-O-phosphonononic acid phosphatase (KDN9P phosphatase) functions in the pathway for the production of 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid, a sialic acid that is important for the survival of commensal bacteria in the human intestine. The enzyme is a member of the haloalkanoate dehalogenase superfamily and represents a good model for the active-site protonation state of family members. Crystals of approximate dimensions 1.5 x 1.0 x 1.0 mm were obtained in space group P2(1)2(1)2, with unit-cell parameters a = 83.1, b = 108.9, c = 75.7 angstrom. A complete neutron data set was collected from a medium-sized H/D-exchanged crystal at BIODIFF at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany in 18 d. Initial refinement to 2.3 angstrom resolution using only neutron data showed significant density for catalytically important residues.

• 出版日期2013-9