The methylthiolation reaction mediated by the Radical-SAM enzymes

Over the past 10 years, considerable progress has been made in our understanding of the mechanistic enzymology of the Radical-SAM enzymes. It is now clear that these enzymes appear to be involved in a remarkably wide range of chemically challenging reactions. This review article highlights mechanistic and structural aspects of the methylthiotransferases (MTTases) sub-class of the Radical-SAM enzymes. The mechanism of methylthio insertion, now observed to be performed by three different enzymes is an exciting unsolved problem. This article is part of a Special Issue entitled: Radical SAM enzymes and Radical Enzymology.

► Activation of the CH bonds is intricately linked to the presence of a metal ion. ► SAM-dependent radical-based modification of biological macromolecules. ► The methylthiolation reaction mediated by the Radical-SAM enzymes. ► Phylogenetic and sequence analysis of the MTTase family. ► Structural organization of MTTase enzymes.