Molybdenum enzymes, their maturation and molybdenum cofactor biosynthesis in Escherichia coli

► We provide an update on molybdenum cofactor (Moco) biosynthesis in Escherichia coli. ► New variants of Moco were identified in E. coli, like MCD and sulfurated bis-MGD. ► An overview of the localization and function of molybdoenzymes in the cell is given. ► The insertion Moco is a complex process which is explained by the TorA-TorD system.