The enzymes in ubiquitin-like post-translational modifications.

Ubiquitin and at least ten ubiquitin-like proteins are important post-translational modifiers that regulate nearly every aspect of cellular function. These modifications require several chemical reactions that are catalyzed by at least three enzymes. Significant progress has been made in the structure-function analysis of these enzymes. This review describes new advancements in an understanding of the mechanisms of the enzymes catalyzing ubiquitin-like modifications, and highlights the important problems that remain to be addressed.