Peptidoglycan (PG), an essential component of bacterial cell wall, protects bacterial cells from changes in osmotic pressure and helps to maintain cell shape. PG is constructed from short peptide chains and two carbohydrates, N-acetyl-glucosamine (GlcNAc) and N-acetyl-muramic acid (MurNAc). We recently developed a method combined organic synthesis, biochemistry, and genetic engineering approaches to label Escherichia coli bacterial PG on its MurNAc sugar backbone. Unnatural PG intermediates with bioorthogonal functionalization were synthesized and incorporated into PG via a specific cell wall recycling pathway. Remodeled cells were then labeled with a bioorthogonal click reaction to link a fluorescent molecule onto the cell wall. Using this method, the bacterial cell wall including the dividing PG-ring was successfully visualized and analyzed by Structured Illumination Microscopy (SIM) and Stochastic Optical Reconstruction Microscopy (STORM). To achieve a better understanding of the dynamics and three-dimensional architecture of bacterial cell wall during cell division, we engineered the E. coli cell strain to label on the bacterial tubulin FtsZ, a protein serves as the scaffold of divisome assembly. Dual labeling on the bacterial PG and FtsZ protein provides a new approach to study the interaction between PG carbohydrate and cell divisome, and the forming of Z-ring during cell division. This study would also help to reveal new details about the assembly order during cell wall dividing and determine that whether the PG biosynthesis or FtsZ polymer constriction provides the force for cell division.

Dual labeling of bacterial peptidoglycan and tubulin FtsZ to study bacterial cell division

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.