Together with AlgI and AlgV, forms an inner membrane complex which probably interacts with the alginate polymerization- transport complex and adds acetyl groups at the O-2 and O-3 positions of polymannuronic acid. Acetylation of alginate increases cyst resistance to desiccation. Alginate biosynthesis protein AlgF ALGF_AZOVI algF 217 MTRLHRKHRIALGLGLGLLLGFGGTTVQAAGDAALYEAVAPKGSTFVRLYNASNQEVSANVGSINLEDVSPLSSSGFEYLPAGQYSARVGSQNLPVNLSAEHYYTLVTQSGAAPLLVEEPAFKSKQKALLRVQNLSDKPLTLKTADGKTEVVKSVEPKGRGDREINPVKANLALFDGERKVADLKPISLARGEVVCLYVTGTANQLNPVWVKPPVKE