Unusual, dual endo- and exonuclease activity in the degradosome explained by crystal structure analysis of RNase J1

Structure. 2011 Sep 7;19(9):1241-51. doi: 10.1016/j.str.2011.06.017.

Abstract

RNase J is an essential enzyme in Bacillus subtilis with unusual dual endonuclease and 5'-to-3' exonuclease activities that play an important role in the maturation and degradation of mRNA. RNase J is also a component of the recently identified "degradosome" of B. subtilis. We report the crystal structure of RNase J1 from B. subtilis to 3.0 Å resolution, analysis of which reveals it to be in an open conformation suitable for binding substrate RNA. RNase J is a member of the β-CASP family of zinc-dependent metallo-β-lactamases. We have exploited this similarity in constructing a model for an RNase J1:RNA complex. Analysis of this model reveals candidate-stacking interactions with conserved aromatic side chains, providing a molecular basis for the observed enzyme activity. Comparisons of the B. subtilis RNase J structure with related enzymes reveal key differences that provide insights into conformational changes during catalysis and the role of the C-terminal domain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Bacillus subtilis / enzymology*
  • Catalytic Domain
  • Crystallography, X-Ray
  • Hydrogen Bonding
  • Models, Molecular
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Protein Structure, Quaternary
  • RNA / chemistry
  • Ribonucleases / chemistry*
  • Structural Homology, Protein

Substances

  • RNA
  • Ribonucleases

Associated data

  • PDB/3ZQ4