Hemolysin-coregulated protein, molecular model. This protein is from the bacterium Pseudomonas aeruginosa. It is a hexameric ring structure, named hcp1, that has applications in nanotechnology for the construction of nanotubes. The ring has a 40-angstrom internal diameter. It plays a role in the protein secretion process by which the Pseudomonas aeruginosa bacterium can cause infections. These include wound, lung, skin and urinary tract infections, particularly in hospital patients.