Expression, purification, crystallization and X-ray crystallographic analysis of the periplasmic binding protein VatD fromVibrio vulnificusM2799

Abstract

Vibrio vulnificusis a halophilic marine microorganism which causes gastroenteritis and primary septicaemia in humans. An important factor that determines the survival ofV. vulnificusin the human body is its ability to acquire iron. VatD is a periplasmic siderophore-binding protein fromV. vulnificusM2799. The current study reports the expression, purification and crystallization of VatD. Crystals of both apo VatD and a VatD–desferrioxamine B–Fe3+(VatD–FOB) complex were obtained. The crystal of apo VatD belonged to space groupP6422, while the crystal of the VatD–FOB complex belonged to space groupP21. The difference in the two crystal forms could be caused by the binding of FOB to VatD.