Abstract
SUMMARYLipoic acid-modified proteins are essential for central metabolism and pathogenesis. In recent years, the Escherichia coli and Bacillus subtilis lipoyl assembly pathways have been modified and extended to archaea and diverse eukaryotes including humans. These extensions include a new pathway to insert the key sulfur atoms of lipoate, several new pathways of lipoate salvage, and a novel use of lipoic acid in sulfur-oxidizing bacteria. Other advances are the modification of E. coli LplA for studies of protein localization and protein-protein interactions in cell biology and in enzymatic removal of lipoate from lipoyl proteins. Finally, scenarios have been put forth for the evolution of lipoate assembly in archaea.