Biological Projects

Structural studies of live biofilms (TasA/TapA)

Biofilms are surface-attached communities formed by microorganisms that can serve as protection against host immune reactions or antibiotics. Bacillus subtilis biofilms contain a mixture of proteins, polysaccharides and nucleic acids to support the structural integrity. Our main aim is to characterize the proteinaceous components TasA and TapA by an inter-disciplinary approach of NMR, EM, X-ray diffraction, and analytical ultracentrifugation experiments. We found by MAS NMR of TasA on live biofilms that a structural change towards β-sheet-rich fibrils occurs. Together with our collaborators we work on pinpointing crucial residues and monitor how these affect biofilm formation in vivo. Further studies will help scientists to reveal the secret of biofilm stability and may offer new approaches to fighting pathogens.

 

Reference:

Diehl A, Roske Y, Ball L, Chowdhury A, Hiller M, Molière N, Kramer R, Stöppler D, Worth CL, Schlegel B, Leidert M, Cremer N, Erdmann N, Lopez D, Stephanowitz H, Krause E, van Rossum B-J, Schmieder P, Heinemann U, Turgay K, Akbey Ü, Oschkinat H (2018) Structural changes of TasA in biofilm formation of Bacillus subtilis. PNAS 115, 3237-3242. DOI: 10.1073/pnas.1718102115

Figure 1: Reconstitution of live pellicle biofilm with recombinant TasA protein. Wildtype Bacillus subtilis strains create characteristic wrinkles upon biofilm formation (left). These cannot emerge when the tasA gene is deleted (middle) but partially develop upon the addition of recombinantly produced TasA protein (right).

Figure 2: TasA occupies a fibral state when in biofilm environment. TasA fibers can be produced in vitro from 13C, 15N labeled protein, and analyzed by solid-state NMR (red). Supplying labeled protein to TasA deficient bacteria leads to biofilm integration (compare also Figure 1). This selectively NMR active biofilm can be measured (blue) and yields a comparable spectrum to in vitro grown fibers.

(click on image to enlarge)

Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP)
Campus Berlin-Buch
Robert-Roessle-Str. 10
13125 Berlin, Germany
+4930 94793 - 100 
+4930 94793 - 109 (Fax)
info(at)fmp-berlin.de

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