Required for cellulose biosynthesis (PubMed:11929533). May have protease activity (PubMed:11929533), but BcsA is not targeted (PubMed:24942809). Binds bis-(3'-5') cyclic diguanylic acid (c-di-GMP) (PubMed:24942809). Mutants lack the ability to produce a biofilm. Belongs to the BcsE family.