title: Attachment of Streptomyces coelicolor is mediated by amyloidal fimbriae that are anchored to the cell surface via cellulose.
abstract: The chaplin proteins ChpA-H enable the filamentous bacterium Streptomyces coelicolor to form reproductive aerial structures by assembling into surface-active amyloid-like fibrils. We here demonstrate that chaplins also mediate attachment of S. coelicolor to surfaces. Attachment coincides with the formation of fimbriae, which are connected to the cell surface via spike-shaped protrusions. Mass spectrometry, electron microscopy and Congo red treatment showed that these fimbriae are composed of bundled amyloid fibrils of chaplins. Attachment and fimbriae formation were abolished in a strain in which the chaplin genes chpA-H were inactivated. Instead, very thin fibrils emerged from the spike-shaped protrusions in this mutant. These fibrils were susceptible to cellulase treatment. This enzymatic treatment also released wild-type fimbriae from the cell surface, thereby abolishing attachment. The reduced attachment of a strain in which the gene of a predicted cellulose synthase was inactivated also indicates a role of cellulose in surface attachment. We propose that the mechanism of attachment via cellulose-anchored amyloidal fimbriae is widespread in bacteria and may function in initiation of infection and in formation of biofilms.
authors.affiliation: Groningen Biomolecular Sciences and Biotechnology Institute (GBB), Department of Microbiology, University of Groningen, Haren, The Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: de Jong
authors.forename: Han A B
authors.initials: HA
authors.lastname: Wösten
authors.forename: Lubbert
authors.initials: L
authors.lastname: Dijkhuizen
authors.forename: Dennis
authors.initials: D
authors.lastname: Claessen
mesh_terms: D001422:Bacterial Adhesion; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism*; D003224:Congo Red / Q000494:pharmacology; D010861:Fimbriae, Bacterial / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D007202:Indicators and Reagents / Q000494:pharmacology; D013058:Mass Spectrometry; D008854:Microscopy, Electron; D011485:Protein Binding; D048372:Streptomyces coelicolor / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D007202:Indicators and Reagents; D003224:Congo Red; D002482:Cellulose