Expression, purification and preliminary crystallographic analysis of a haem-utilizing protein, HutX, from Vibrio cholerae

Vibrio cholerae, the causative agent of cholera, has developed a variety of mechanisms to obtain the limited-availability iron from human hosts. One important method for iron acquisition is through haem-uptake systems. Although the transport of haem has been widely studied, the fate of haem once it enters the cytoplasm remains an open question. Here, preliminary X-ray crystallographic analysis was performed on HutX, a member of the conserved haem-utilization operon from V. cholerae strain N16961. The crystals of HutX were found to belong to the orthorhombic space group C222₁, with unit-cell parameters a = 50.1, b = 169.0, c = 81.8 Å. There are two protein molecules in the asymmetric unit, with a corresponding Matthews coefficient V_M of 2.06 ų Da⁻¹ and a solvent content of 40.28%.