| Structural highlights
Function
TAPA_BACSU Required for biofilm formation (PubMed:16430695, PubMed:16430696, PubMed:21477127, PubMed:24488317). Required for the proper anchoring and polymerization of TasA amyloid fibers at the cell surface (PubMed:16430696, PubMed:21477127, PubMed:24488317). Is also a minor component of TasA fibers (PubMed:21477127).[1] [2] [3] [4]
Publication Abstract from PubMed
Studying mechanisms of bacterial biofilm generation is of vital importance to understanding bacterial cell-cell communication, multicellular cohabitation principles, and the higher resilience of microorganisms in a biofilm against antibiotics. Biofilms of the nonpathogenic, gram-positive soil bacterium Bacillus subtilis serve as a model system with biotechnological potential toward plant protection. Its major extracellular matrix protein components are TasA and TapA. The nature of TasA filaments has been of debate, and several forms, amyloidic and non-Thioflavin T-stainable have been observed. Here, we present the three-dimensional structure of TapA and uncover the mechanism of TapA-supported growth of nonamyloidic TasA filaments. By analytical ultracentrifugation and NMR, we demonstrate TapA-dependent acceleration of filament formation from solutions of folded TasA. Solid-state NMR revealed intercalation of the N-terminal TasA peptide segment into subsequent protomers to form a filament composed of beta-sandwich subunits. The secondary structure around the intercalated N-terminal strand beta0 is conserved between filamentous TasA and the Fim and Pap proteins, which form bacterial type I pili, demonstrating such construction principles in a gram-positive organism. Analogous to the chaperones of the chaperone-usher pathway, the role of TapA is in donating its N terminus to serve for TasA folding into an Ig domain-similar filament structure by donor-strand complementation. According to NMR and since the V-set Ig fold of TapA is already complete, its participation within a filament beyond initiation is unlikely. Intriguingly, the most conserved residues in TasA-like proteins (camelysines) of Bacillaceae are located within the protomer interface.
TapA acts as specific chaperone in TasA filament formation by strand complementation.,Roske Y, Lindemann F, Diehl A, Cremer N, Higman VA, Schlegel B, Leidert M, Driller K, Turgay K, Schmieder P, Heinemann U, Oschkinat H Proc Natl Acad Sci U S A. 2023 Apr 25;120(17):e2217070120. doi: , 10.1073/pnas.2217070120. Epub 2023 Apr 17. PMID:37068239[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Chu F, Kearns DB, Branda SS, Kolter R, Losick R. Targets of the master regulator of biofilm formation in Bacillus subtilis. Mol Microbiol. 2006 Feb;59(4):1216-28. doi: 10.1111/j.1365-2958.2005.05019.x. PMID:16430695 doi:http://dx.doi.org/10.1111/j.1365-2958.2005.05019.x
- ↑ Branda SS, Chu F, Kearns DB, Losick R, Kolter R. A major protein component of the Bacillus subtilis biofilm matrix. Mol Microbiol. 2006 Feb;59(4):1229-38. doi: 10.1111/j.1365-2958.2005.05020.x. PMID:16430696 doi:http://dx.doi.org/10.1111/j.1365-2958.2005.05020.x
- ↑ Romero D, Vlamakis H, Losick R, Kolter R. An accessory protein required for anchoring and assembly of amyloid fibres in B. subtilis biofilms. Mol Microbiol. 2011 Jun;80(5):1155-68. doi: 10.1111/j.1365-2958.2011.07653.x., Epub 2011 May 5. PMID:21477127 doi:http://dx.doi.org/10.1111/j.1365-2958.2011.07653.x
- ↑ Romero D, Vlamakis H, Losick R, Kolter R. Functional analysis of the accessory protein TapA in Bacillus subtilis amyloid fiber assembly. J Bacteriol. 2014 Apr;196(8):1505-13. doi: 10.1128/JB.01363-13. Epub 2014 Jan 31. PMID:24488317 doi:http://dx.doi.org/10.1128/JB.01363-13
- ↑ Roske Y, Lindemann F, Diehl A, Cremer N, Higman VA, Schlegel B, Leidert M, Driller K, Turgay K, Schmieder P, Heinemann U, Oschkinat H. TapA acts as specific chaperone in TasA filament formation by strand complementation. Proc Natl Acad Sci U S A. 2023 Apr 25;120(17):e2217070120. PMID:37068239 doi:10.1073/pnas.2217070120
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