Open AccessPreliminary X‐ray crystallographic analysis of the d ‐xylulose 5‐phosphate phosphoketolase from Lactococcus lactis
Author(s) -
Petrareanu Georgiana,
Balasu Mihaela C.,
Zander Ulrich,
Scheidig Axel J.,
Szedlacsek Stefan E.
Publication year - 2010
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s174430911001732x
Subject(s) - lactococcus lactis , chemistry , biochemistry , phosphorolysis , enzyme , thiamine , phosphate , transketolase , stereochemistry , bacteria , biology , lactic acid , genetics , purine nucleoside phosphorylase , purine
Phosphoketolases are thiamine diphosphate‐dependent enzymes which play a central role in the pentose‐phosphate pathway of heterofermentative lactic acid bacteria. They belong to the family of aldehyde‐lyases and in the presence of phosphate ion cleave the carbon–carbon bond of the specific substrate d ‐xylulose 5‐phosphate (or d ‐fructose 6‐phosphate) to give acetyl phosphate and d ‐glyceraldehyde 3‐phosphate (or d ‐erythrose 4‐phosphate). Structural information about phosphoketolases is particularly important in order to fully understand their mechanism as well as the steric course of phosphoketolase‐catalyzed reactions. Here, the purification, preliminary crystallization and crystallographic characterization of d ‐xylulose 5‐phosphate phosphoketolase from Lactococcus lactis are reported. The presence of thiamine diphosphate during purification was essential for the enzymatic activity of the purified protein. The crystals belonged to the monoclinic space group P 2 1 . Diffraction data were obtained to a resolution of 2.2 Å.