Architecture of cell-cell junctions in situ reveals a mechanism for bacterial biofilm inhibition.

Many bacteria, including the major human pathogen , are naturally found in multicellular, antibiotic-tolerant biofilm communities, in which cells are embedded in an extracellular matrix of polymeric molecules. Cell-cell interactions within biofilms are mediated by CdrA, a large, membrane-associated adhesin present in the extracellular matrix of biofilms, regulated by the cytoplasmic concentration of cyclic diguanylate. Here, using electron cryotomography of focused ion beam-milled specimens, we report the architecture of CdrA molecules in the extracellular matrix of biofilms at intact cell-cell junctions.