crystallization communications
D-threo-3-Hydroxyaspartate dehydratase (D-THA DH) isolated from the soil bacterium Delftia sp. HT23 is a novel enzyme consisting of 380 amino-acid residues which catalyzes the conversion of D-threo-3-hydroxyaspartate to oxaloacetate and ammonia. D-THA DH also catalyzes the dehydration of L-threo-3-hydroxyaspartate, L-erythro-3-hydroxyaspartate and D-serine. The amino-acid sequence of D-THA DH shows significant similarity to that of two eukaryotic D-serine dehydratases derived from Saccharomyces cerevisiae and chicken kidney. D-THA DH is classified into the fold-type III group of pyridoxal enzymes and is the first example of a fold-type III dehydratase derived from a prokaryote. Overexpression of recombinant D-THA DH was carried out using a Rhodococcus erythropolis expression system and the obtained protein was subsequently purified and crystallized. The crystals of D-THA DH belonged to space group I4122, with unit-cell parameters a = b = 157.3, c = 157.9 Å. Single-wavelength anomalous diffraction data were collected to a resolution of 2.0 Å using synchrotron radiation at the wavelength of the Br K absorption edge.
Keywords: alanine racemase; Br-SAD; Delftia sp. HT23; D-threo-3-hydroxyaspartate dehydratase; pyridoxal 5'-phosphate.
Supporting information
Portable Document Format (PDF) file https://doi.org/10.1107/S1744309113023956/no5025sup1.pdf |