Tandem Hydration of Diisonitriles Triggered by Isonitrile Hydratase in Streptomyces thioluteus

The biosynthetic pathway of diisonitrile chalkophore SF2768 was identified in Streptomyces thioluteus through heterologous expression recently. Isolation and structure elucidation of the N-substituted formamides that coexisted with the diisonitriles implied that a hydration event was involved. In vitro enzymatic assays of an endogenous isonitrile hydratase suggested a rare sequential-hydration of the diisonitriles. Additionally, the results of Cu-CAS assays indicate that both partial and complete hydration led to the loss of the copper-chelating ability of SF2768.