Bifunctionality of a biofilm matrix protein controlled by redox state.
Sofia ArnaouteliAna Sofia FerreiraMarieke SchorRyan J MorrisKeith M BromleyJeanyoung JoKrista L CortezTetyana SukhodubAlan R PrescottLars E P DietrichCait E MacPheeNicola R Stanley-WallPublished in: Proceedings of the National Academy of Sciences of the United States of America (2017)
Biofilms are communities of microbial cells that are encapsulated within a self-produced polymeric matrix. The matrix is critical to the success of biofilms in diverse habitats; however, many details of the composition, structure, and function remain enigmatic. Biofilms formed by the Gram-positive bacterium Bacillus subtilis depend on the production of the secreted film-forming protein BslA. Here, we show that a gradient of electron acceptor availability through the depth of the biofilm gives rise to two distinct functional roles for BslA and that these roles can be genetically separated through targeted amino acid substitutions. We establish that monomeric BslA is necessary and sufficient to give rise to complex biofilm architecture, whereas dimerization of BslA is required to render the community hydrophobic. Dimerization of BslA, mediated by disulfide bond formation, depends on two conserved cysteine residues located in the C-terminal region. Our findings demonstrate that bacteria have evolved multiple uses for limited elements in the matrix, allowing for alternative responses in a complex, changing environment.
Keyphrases
- candida albicans
- amino acid
- pseudomonas aeruginosa
- staphylococcus aureus
- bacillus subtilis
- biofilm formation
- cancer therapy
- healthcare
- cell cycle arrest
- protein protein
- microbial community
- binding protein
- cystic fibrosis
- room temperature
- escherichia coli
- gram negative
- cell death
- small molecule
- oxidative stress
- cell proliferation
- pi k akt