Specifically, it is an outer membrane protein that promotes adhesion to tracheal epithelial cells.

[2] A large part of the N-terminus of the pertactin protein is composed of beta helix repeats.

[4] The loops in the right handed β-helix of the N-terminus that protrudes out of cell surface (region R1) contains sequence repeats Gly-Gly-Xaa-Xaa-Pro and the RGD domain Arg-Gly-Asp.

[4] This RGD domain allows PRN to function as an adhesin and invasin, binding to integrins on the outer membrane of the cell.

With respect to the adaptive immunity, studies show that PRN plays a role in combating neutrophil-mediated clearance of B.