Expression, purification, crystallization and crystallographic analysis of the N‐terminal domain of translocated intimin receptor

Translocated intimin receptor (Tir) is an Escherichia coli ‐encoded protein that is transported into the host cell through a sophisticated bacterial type III secretion system (T3SS). Tir anchors the infected cell membrane twice using both its N‐ and C‐termini from inside the host cytoplasm for signalling. It plays a key role in enterohemorrhagic Escherichia coli (EHEC) infection, attaching and effacing (A/E) lesions and intracellular signal transduction. Here, the overexpression, purification and crystallization of its N‐terminal intracellular domain are reported. The crystal belonged to the orthorhombic space group I 4 1 22, with unit‐cell parameters a = b = 59.79, c = 183.11 Å. The asymmetric unit contained one molecule, with a solvent content of 51% and a V M of 2.55 Å 3  Da −1 .