Mediates phase variation of the LPS epitopes. Phase variation of H.influenza LPS epitopes expressed by LicA is determined by a translational switch (By similarity). Lipopolysaccharide (LPS) is a glycolipid that is a necessary component and antigenic determinant of the outer membrane and has been shown to be an important factor in the host-parasite interaction in a number of Gram-negative species. H.influenzae is able to display an extensive repertoire of different surface configurations through variability of its LPS oligosaccharide. Belongs to the peptidase S49 family.