May be involved in the production and the transport of exopolysaccharides. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Glycan metabolism; exopolysaccharide biosynthesis. Autophosphorylated on several Tyr residues. Dephosphorylated by ptp. Belongs to the etk/wzc family.