Most bacteria contain a peptidoglycan cell wall that encapsulates the bacterial cytoplasmic membrane, maintaining cell shape and integrity. While the cell wall is a major target for antibiotics, very few target the initial steps of peptidoglycan biosynthesis that occurs in the cytoplasm. This involves a series of Mur enzymes which catalyse the formation of the important intermediate UDP-MurNAc-pentapeptide. While the Mur enzymes are usually expressed as seperate proteins, in some bacteria they are synthesised as naturally ocurring chimeric proteins, such as MurC-Ddl in Chlamydial species. Unlike most chimeric proteins, the MurC and Ddl enzymes do not catalyse sequential reactions but may be linked due to allostery between the two enzymatic domains; the Ddl domain was inhibited by UDP-MurNAc and UDP-MurNAc-Ala, a substrate and product of MurC respectively, as well as an inhibitor of MurC. The structure of MurC-Ddl was resolved to 2.8 Å and revealed the MurC inhibitor bound to the MurC domain only. Additionally, MurC and Ddl could be fused in Chlamydia for stability since neither of these enzymatic domains could be expressed as isolated proteins that retained activity. Ddl in particular was completely unstable and may require the MurC domain to stabilise a large α-helix protruding from the protein that occurs at the C-terminus of Ddl. The clinical targeting of Mur ligases, such as MurC, remains under-developed and therefore these enzymes could represent good targets for the development of novel antibiotics. Since MurC and Ddl share a similar catalytic mechanism, MurC-Ddl could be amenable to multi-target inhibitors and the structure of MurC-Ddl may help direct the future development of novel inhibitors targeting this chimera. Furthermore, MurC inhibitors are likely to target other Mur ligases owing to their common structure and catalytic mechanism.