Abstract
Summary Peptidoglycan is a major determinant of cell shape in bacteria, and its biosynthesis involves the concerted action of cytoplasmic, membrane‐associated and periplasmic enzymes. Within the cytoplasm, M ur enzymes catalyse the first steps leading to peptidoglycan precursor biosynthesis, and have been suggested as being part of a multicomponent complex that could also involve the transglycosylase M ur G and the cytoskeletal protein M re B . In order to initialize the characterization of a potential M ur interaction network, we purified M ur D , M ur E , M ur F , M ur G and M re B from T hermotoga maritima and characterized their interactions using membrane blotting and surface plasmon resonance. M ur D , M ur E and M ur F all recognize M ur G and M re B , but not each other, while the two latter proteins interact. In addition, we solved the crystal structures of M ur D , M ur E and M ur F , which indicate that their C ‐termini display high conformational flexibilities. The differences in M ur conformations could be important parameters for the stability of an intracytoplasmic murein biosynthesis complex.