Open AccessNeutron diffraction studies towards deciphering the protonation state of catalytic residues in the bacterial KDN9P phosphatase
Author(s) -
Bryan Tyrel,
González Javier M.,
Bacik John P.,
DeNunzio Nicholas J.,
Unkefer Clifford J.,
Schrader Tobias E.,
Ostermann Andreas,
DunawayMariano Debra,
Allen Karen N.,
Fisher S. Zoë
Publication year - 2013
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309113021386
Subject(s) - protonation , enzyme , chemistry , neutron diffraction , acid phosphatase , crystallography , sialic acid , active site , phosphatase , biochemistry , crystal structure , organic chemistry , ion
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 × 1.0 × 1.0 mm were obtained in space group P 2 1 2 1 2, with unit‐cell parameters a = 83.1, b = 108.9, c = 75.7 Å. 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 Å resolution using only neutron data showed significant density for catalytically important residues.