Dr. Petya Krasteva - Microbial biofilm matrix secretion: Mechanisms for activation and diversification of the bacterial cellulose synthase - IPBS-Toulouse, Seminar Room

Petya Krasteva

IECB (Institut Européen de Chimie et Biologie), Bordeaux

Microbial biofilm matrix secretion: Mechanisms for activation and diversification of the bacterial cellulose synthase

Bacterial biofilms are a prevalent multicellular life form in which individual members can undergo significant functional differentiation and are typically embedded in complex extracellular matrix of proteinaceous fimbriae, extracellular DNA and exopolysaccharides (EPS). Bacteria have evolved at least four major mechanisms for EPS biosynthesis, of which the synthase-dependent systems for bacterial cellulose secretion (Bcs) represent not only key biofilm determinants in a wide array of environmental, endosymbiotic and pathogenic microbes, but also an important model system for the studies of processive glycan polymerization, c-di-GMP-dependent synthase regulation and biotechnological polymer applications. The secreted cellulosic chains can be decorated with additional chemical groups to provide for specific interactions with other biofilm- or host-derived extracellular components or can pack with various degrees of crystallinity depending on dedicated enzymatic complexes and/or cytoskeletal scaffolds. Here I will present recent progress in our understanding of synthase-dependent EPS biogenesis with focus on common and idiosyncratic molecular mechanisms across diverse cellulose secretion systems.
Selected references

• Anso I, Zouhir S, Sana T and Krasteva PV. Structural basis for synthase activation and cellulose modification in the E. coli Type II Bcs secretion system. Nature Communications 15: 8799 (2024)
• Anso I, Gayral D and Krasteva PV. Cellulose and cellulose secretion in bacterial biofilms. Biofilm Matrix. Springer Series on Biofilms vol. 13 (2024)
• Krasteva PV. Bacterial synthase-dependent exopolysaccharide secretion: a focus on cellulose. Curr Opin Microbiol 79: 102476 (2024)
• Sana TG*, Notopoulou A*, Puygrenier L, Decossas M, Moreau S, Carlier A and Krasteva PV. Structures and Roles of BcsD and Partner Scaffold Proteins in Proteobacterial Cellulose Secretion' Current Biology 13: S0960-9822(23)01645-7 (2024)
• Abidi W*, Decossas M*, Torres-Sánchez L*, Puygrenier L, Létoffé S, Ghigo JM and Krasteva PV. Bacterial crystalline cellulose secretion via a supramolecular BcsHD scaffold. Science Advances 8, eadd1170 (2022)
• Abidi W*, Torres-Sánchez L*, Siroy A* and Krasteva PV. Weaving of bacterial cellulose by the Bcs secretion systems. FEMS Microbiology Reviews fuab051 (2021)
• Abidi W*, Zouhir S*, Caleechurn M, Roche S and Krasteva PV. Architecture and regulation of an enterobacterial cellulose secretion system. Science Advances 7 (5): eabd8049 (2021)
• Zouhir S*, Abidi W*, Caleechurn M and Krasteva PV. Structure and multitasking of the c-di-GMP-sensing cellulose secretion regulator BcsE. mBio 11: e01303-20 (2020)
• Krasteva PV*, Bernal-Bayard J*, Travier L, Martín FA, Kaminski PA, Karimova G, Fronzes R and Ghigo JM. Insights into the structure and assembly of a bacterial cellulose secretion system. Nature Communications 8 (1): 2065 (2017)
• Krasteva PV and Sondermann H. Versatile modes of cellular regulation via cyclic dinucleotides. Nature Chemical Biology 13: 350-359 (2017)

The organization of this seminar is supported by the SFR-B2S Federation.