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Detecting Cortex Fragments During Bacterial Spore Germination
Published on: June 25, 2016
A highly coordinated cell wall degradation machine governs spore morphogenesis in Bacillus subtilis
Cecile Morlot1, Tsuyoshi Uehara, Kathleen A Marquis
1Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Genes & Development
|February 18, 2010
Summary
Bacterial cell wall remodeling during sporulation involves a protein complex that degrades peptidoglycan. This complex, with sequential and stimulatory activities, drives mother cell engulfment of the spore.
Area of Science:
- Developmental biology
- Microbiology
- Cell biology
Background:
- Morphogenesis in bacteria is linked to cell wall remodeling.
- Understanding protein-catalyzed morphogenesis is crucial in developmental biology.
Purpose of the Study:
- Investigate the mechanism of mother cell engulfment of the spore during Bacillus subtilis sporulation.
- Elucidate the roles of a membrane-anchored protein complex in cell wall hydrolysis.
Main Methods:
- Biochemical characterization of protein activities (amidase, endopeptidase, lytic transglycosylase).
- Analysis of protein-protein interactions and substrate binding.
- In vivo studies of sporulation in Bacillus subtilis.
Main Results:
- Identified a protein complex with two cell wall hydrolases, SpoIIP and SpoIID.
- SpoIIP exhibits amidase and endopeptidase activity, cleaving stem peptides and cross-links.
- SpoIID, a novel lytic transglycosylase, degrades glycan strands into disaccharides.
- SpoIID activity is dependent on prior stem peptide removal and enhances SpoIIP activity.
Conclusions:
- The SpoIIP-SpoIID complex provides sequential and complementary cell wall degradation.
- This coordinated enzymatic activity facilitates processive cell wall breakdown.
- The complex acts as a motor, enabling mother cell membrane engulfment of the forespore during sporulation.
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