Expression and purification of SfaXII, a protein involved in regulating adhesion and motility genes in extraintestinal pathogenic Escherichia coli

► We developed a purification protocol for SfaX, a transcriptional regulator in extraintestinal pathogenic Escherichia coli ExPEC. ► We built a molecular model of SfaXII using the molecular modeling program MODELLER. ► We engineered a mutation that improved solubility of the protein. ► The structural properties and thermostability of purified SfaXIIC70S were verified. ► We demonstrated that the protein possesses DNA-binding properties.