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 Å resolution at 100 K using 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 Å, α=82.8, β=68.2, γ=83.0°. The asymmetric unit contained eight subunits of xylose isomerase with a crystal volume per protein weight (VM) of 2.38 Å3 Da(-1) and a solvent content of 48.3%.