Genetic and Biochemical Characterization of Peptidoglycan Synthesis in Chlamydia

摘要

The Chlamydiaceae family of bacteria are obligate, intracellular pathogens that cause significant diseases world-wide in both humans and animals. Despite having a cell envelope that resembles other gram-negative bacteria, the presence of peptidoglycan in the Chlamydia cell envelope has long been debated. Unlike other wall-less bacteria, chlamydiae synthesize penicillin- binding proteins, are sensitive to antibiotics that inhibit cell wall synthesis, and encode a nearly complete pathway for the synthesis of peptidoglycan. However, peptidoglycan has yet to be detected. In this work, the functionality of the peptidoglycan synthesis pathway in C. trachomatis was examined by genetically and biochemically characterizing key enzymes in the pathway. The characterization of key enzymes in the PG synthesis pathway of Chlamydia suggests that these organisms synthesize PG and that the chlamydial PG structure is of the same composition as PG in other gram-negative bacteria. Furthermore, these findings pave the way for future research to answer the questions of how, when and why PG is synthesized in Chlamydia. The functionality of the PG synthesis pathway in Chlamydia opens the door to discovery of new and the use of pre-existing cell wall inhibitors for the treatment of chlamydial infections.