Abstract - Krasteva

Bacterial cellulosic polymers constitute a prevalent class of biofilm matrix exopolysaccharides that are synthesized by several types of bacterial cellulose secretion (Bcs) systems, which include conserved cyclic diguanylate (c-di-GMP)-dependent cellulose synthase modules together with diverse accessory subunits. In E. coli, the biogenesis of phosphoethanolamine (pEtN)-modified cellulose relies on the BcsRQABEFG macrocomplex, encompassing inner membrane and cytosolic subunits, a periplasmic endonuclease (BcsZ) and an outer membrane porin (BcsC). In other species, cellulose secretion relies on cytoskeletal scaffolds for synthase array formation and activation, and the secreted polymer can undergo supramolecular packing or alternative chemical modifications. I will present recent progress in our understanding of the molecular mechanisms of synthase activation, nano-array formation and polymer modification across Bcs secretion machineries.