It is an attaching and effacing (A/E) protein, which with other virulence factors is necessary and responsible for enteropathogenic and enterohaemorrhagic diarrhoea.

Once within the cytoplasm of the host cell, Tir is inserted into the plasma membrane, allowing surface exposure and intimin binding.

It is a 94 kDa outer membrane protein encoded by eaeA gene in the locus of enterocyte effacement (LEE), a 35-Kb pathogenicity island.

[4] Mutations in the eaeA gene result in loss of ability to cause A/E lesions, and is required for full virulence in infected volunteers and animal models.

[5] The N-terminal domains of intimin from A/E lesion forming pathogens have high homology with each other and to invasin from Yersinia pseudotuberculosis and Yersinia enterocolitica, whereas the C-terminal domains show less homology.