Expression, purification, crystallization and preliminary crystallographic analysis of Cg1458: a novel oxaloacetate decarboxylase from Corynebacterium glutamicum

Oxaloacetate decarboxylase catalyses the decarboxylation of oxaloacetate to pyruvate and CO₂. Recently, the Corynebacterium glutamicum gene product Cg1458 was determined to be a soluble oxaloacetate decarboxylase. To elucidate the mechanism of oxaloacetate decarboxylation by Cg1458, recombinant Cg1458 was purified and crystallized. The best crystal was grown from 0.2 M MgCl₂, 0.1 M Bis-Tris pH 6.0, 25%(w/v) polyethylene glycol 3350 using the hanging-drop method. The crystals belonged to space group P4₃2₁2, with unit-cell parameters a = b = 124.1, c = 73.6 Å. The crystals are most likely to contain a dimer in the asymmetric unit, with a V_M value of 2.27 Å³ Da^-1. A full data set was collected at 1.9 Å resolution using synchrotron radiation on beamline BL17U of SSRF, Shanghai, China. Structure-solution attempts by molecular replacement were successful with PDB entries 3qdf or 2dfu as the template.