Structure of transglutaminases: Unique features serve diverse functions

Abstract

Understanding the diverse functions and pathologies of transglutaminases requires detailed analysis and interpretation of their structures. This chapter is an attempt to describe in detail how these enzymes are folded into functional domains, what type of catalytic and scaffolding functions have been gained as the result of their evolution, how their regulation is achieved through unique Ca2+ and purine nucleotide binding sites, redox changes and specific proteolytic actions, and by influencing the equilibrium of open-close configurations. The importance of structural motifs in pathologies is underlined by the celiac epitopes of transglutaminase 2, responsible for autoimmune reactions.