Overexpression, crystallization and preliminary X-ray crystallographic analysis of a putative xylose isomerase from Bacteroides thetaiotaomicron

Bacteroides thetaiotaomicron BT0793, a putative xylose isomerase, was overexpressed in Escherichia coli, purified and crystallized using polyethylene glycol monomethyl ether 550 as the precipitant. X-ray diffraction data were collected to 2.10 angstrom resolution at 100 Kusing synchrotron X-rays. The crystal was found to belong to space group P1, with unit-cell parameters a = 96.3, b = 101.7, c = 108.3 angstrom, alpha = 82.8, beta = 68.2, gamma = 83.0 degrees. The asymmetric unit contained eight subunits of xylose isomerase with a crystal volume per protein weight (V-M) of 2.38 angstrom(3) Da(-1) and a solvent content of 48.3%.