TasA is the major protein component of the biofilm extracellular matrix (PubMed:16430696, PubMed:20080671). It forms amyloid fibers that bind cells together in the biofilm (PubMed:20080671). Exhibits an antibacterial activity against a variety of Gram-positive and Gram-negative bacteria (PubMed:10049401). In laboratory strains, is also involved in proper spore coat assembly (PubMed:10368135). Forms fibers (PubMed:20080671, PubMed:29531041). Fibers have variable length and are 10-15 nm width (PubMed:20080671). Interacts with obg (AC P20964) in pull-down experiments (PubMed:12429099). In undomesticated strains, is secreted and primarily associated with the extracellular matrix (PubMed:16430696). In laboratory strains, is secreted into the medium early in sporulation and is also incorporated into the spore. Processing, export and incorporation into spores depend on SipW (PubMed:10049401). In laboratory strains, is a transition-phase protein that is expressed early in spore formation, as cells enter stationary phase (PubMed:10049401, PubMed:10368135, PubMed:10464223). Expression can occur as cells enter stationary phase even under sporulation-repressing conditions (PubMed:10464223). Part of the tapA-sipW-tasA operon (PubMed:10464223). Expression is directly repressed by the DNA-binding protein master regulator of biofilm formation SinR and activated by the extracellular matrix regulatory protein RemA (PubMed:16430695, PubMed:23646920). Also positively regulated by the sporulation transcription factors sigma H and Spo0A and repressed by the transition phase regulatory protein AbrB, probably indirectly (PubMed:10049401, PubMed:10368135, PubMed:10464223). Mutation impairs colony surface architecture (PubMed:16430695). Mutant forms pellicles with less extracellular material (PubMed:16430696). Deletion of the gene results in the production of asymmetric spores that accumulate misassembled material in one pole and have a greatly expanded undercoat and an altered outer coat structure (PubMed:10368135). Belongs to the peptidase M73 family.