Purification, crystallization and preliminary X-ray analysis of the galacto-N-biose-/lacto-N-biose I-binding protein (GL-BP) of the ABC transporter from Bifidobacterium longum JCM1217

A recombinant galacto-N-biose-/ lacto-N-biose I-binding protein ( GL-BP) from Bifidobacterium longum JCM1217 has been prepared and crystallized by the hanging-drop vapour-diffusion method using 10 mg ml(-1) purified enzyme, 0.01 M zinc sulfate, 0.1 M MES buffer pH 5.9 -6.4 and 20 -22%( v/ v) PEG MME 550 in the presence of 5 mM disaccharide ligands. Suitable crystals grew after 10 d incubation at 293 K. The crystals belong to space group C222(1), with unit-cell parameters a = 106.3, b = 143.6, c = 114.6 angstrom for the lacto-N-biose I complex and a = 106.4, b = 143.4, c = 115.5 angstrom for the galacto-N-biose complex, and diffracted to 1.85 and 1.99 angstrom resolution, respectively.