RNA recognition and cleavage in archaeal ribosome biogenesis: insights from FAU-1

Abstract

Ribosomal RNA maturation requires nucleases that recognize appropriate precursors and cleave them at defined stages of ribosome assembly. How these activities are organized in archaea remains elusive. Kawai and colleagues determined the crystal structure of the archaeal ribonuclease FAU-1, revealing a homotrimer with peripheral RNA-binding domains and a central assembly formed by its C-terminal domains. The structure identifies similarities to the RNA-recognition region of bacterial ribonuclease (RNase) E while exposing substantial differences in overall architecture. Subsequent work assigned FAU-1 to the RNase W family and demonstrated a catalytic role for its C-terminal domain. Together, these studies illustrate how related RNA-recognition elements can operate within distinct nuclease architectures. They also raise questions about the relationship between oligomerization, substrate selection and catalytic activation. Resolving these questions will require analysis of physiological RNA substrates and their associated proteins, connecting the structures of individual processing enzymes to the assembly of functional ribosomes.