What determines bacterial cell wall synthesis?
The bacterial cell wall (CW) is a dynamic structure outside of the cell membrane that maintains cell integrity. It also plays an important role in antibiotic resistance. Some bacteria have evolved mechanisms that allow them to switch between CW and CW-deficient states, also known as L-form. Although little is known about this bacterial process, L-form bacteria are believed to be involved in antibiotic resistance and chronic infections. The EU-funded ‘Discovery and characterization of factors coupling the cytoskeleton to cell wall biogenesis in Bacillus subtilis’ (Rod-Shaping Proteins) project studied what determines cell wall synthesis. Scientists discovered that in the absence of the transporter protein YknWXYZ, the model bacterium Bacillus subtilis showed defects in CW synthesis. Seeking to unravel how bacteria switch from CW to CW-deficient form, project members generated a bacteria strain capable of changing CW state. A genetic screen was performed to identify genes essential for L-form bacterial division. Results indicated that most proteins involved in CW synthesis were dispensable for L-form survival and division. On the other hand, genes involved in cell membrane lipid biosynthesis and several stress conditions proved important for L-form biology. The findings of the Rod-Shaping Proteins project shed light into the functional significance of CW synthesis and its potential role in antibiotic resistance. The data on L-form biology are expected to provide the basis for future investigations on the clinical relevance of these bacterial strains and their potential role in chronic infections. Understanding the basic biology of rod-shaped bacteria has important consequences for the design of new antibiotics as well as managing antibiotic resistance.
