Probably involved in polymerization and/or export of exopolysaccharide EPS I which functions as a virulence factor. May be involved in an ATP-dependent process in the pathway for EPS I production, possibly export of the trimeric repeat units across the inner membrane or their polymerization (By similarity). ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Belongs to the etk/wzc family.