Synthesis and recycling of the mycobacterial cell envelope

•The unique mycobacterial cell wall is a layered structure of carbohydrates and lipids.•The architecture and biosynthesis of the cell wall have largely been elucidated.•Increasing evidence indicates that each cell wall layer is remodelled and recycled.•There are opportunities to discover new essential enzymes in cell wall metabolism.•Cell wall metabolism is a validated source of targets for tuberculosis drug discovery.