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Looking Outwards: Isolation of Cyanobacterial Released Carbohydrate Polymers and Proteins
Published on: May 27, 2019
Synthase-dependent exopolysaccharide secretion in Gram-negative bacteria.
1Program in Molecular Structure and Function, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
Trends in Microbiology
|November 3, 2012
Summary
Bacterial cell-surface polysaccharide secretion involves conserved proteins in Gram-negative bacteria. These systems, including alginate and cellulose, are regulated by cyclic dimeric guanosine monophosphate (c-di-GMP).
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- Bacterial cell-surface polysaccharides are crucial for various functions, including biofilm formation and host interaction.
- Diverse mechanisms exist for polysaccharide biosynthesis and export in bacteria.
- Gram-negative bacteria utilize specific protein machineries for secreting these surface polysaccharides.
Purpose of the Study:
- To compare core protein components in synthase-dependent polysaccharide secretion systems.
- To investigate the roles of conserved proteins in alginate, cellulose, and poly-β-D-N-acetylglucosamine (PNAG) secretion.
- To explore the regulatory role of bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) in these pathways.
Main Methods:
- Comparative analysis of protein structures and biochemical functions.
- Focus on key conserved components: inner-membrane polysaccharide synthase, periplasmic TPR-containing scaffold protein, and outer-membrane β-barrel porin.
- Examination of post-translational regulation by c-di-GMP.
Main Results:
- Identified conserved protein components across different synthase-dependent polysaccharide secretion systems.
- Highlighted the structural and functional similarities of key proteins involved in polysaccharide export.
- Provided evidence for widespread regulation by c-di-GMP in these bacterial pathways.
Conclusions:
- The core machinery for synthase-dependent polysaccharide secretion is conserved in Gram-negative bacteria.
- Understanding these conserved components is vital for deciphering bacterial surface polysaccharide assembly.
- Cyclic dimeric guanosine monophosphate (c-di-GMP) plays a significant regulatory role in polysaccharide secretion.
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