Chapter 1 - Archaeal SF1 and SF2 Helicases: Unwinding in the Extreme

Abstract

Archaea, the third domain of life, are significant microorganism models in understanding fundamental aspects of molecular biology. Since the archaeal informational system shares many eukaryal features, structure–function studies using Archaea as models have largely contributed to our understanding of many eukaryotic cellular processes. Helicases of superfamilies 1 (SF1) and 2 (SF2) have been shown to be of major importance in RNA and DNA metabolism in Eukarya and in Bacteria. In Archaea, the cellular functions of these enzymes remain dispersed and only few members were characterized. In this chapter, we review our knowledge on the archaeal SF1 and SF2 helicases. We focus on phylogenomic studies that revealed archaeal helicase families and give insights into their respective biochemical and structural properties. Finally, we raise the question of the mode of actions of these helicases in archaeal DNA and RNA metabolism.