Characterization of Staphylococcus epidermidis Polynucleotide phosphorylase and its interactions with ribonucleases RNase J1 and RNase J2

Biochem Biophys Res Commun. 2018 Jan 8;495(2):2078-2084. doi: 10.1016/j.bbrc.2017.12.056. Epub 2017 Dec 11.

Abstract

Polynucleotide phosphorylase catalyzes both 3'-5' exoribonuclease and polyadenylation reactions. The crystal structure of Staphylococcus epidermidis PNPase revealed a bound phosphate in the PH2 domain of each protomer coordinated by three adjacent serine residues. Mutational analysis suggests that phosphate coordination by these serine residues is essential to maintain the catalytic center in an active conformation. We note that PNPase forms a complex with RNase J1 and RNase J2 without substantially altering either exo-ribonuclease or polyadenylation activity of this enzyme. This decoupling of catalytic activity from protein-protein interactions suggests that association of these endo- or exo-ribonucleases with PNPase could be more relevant for cellular localization or concerted targeting of structured RNA for recycling.

Keywords: Multi-protein assembly; Phosphorolysis; Polyadenylation; RNA degradation; Ribonuclease activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Enzyme Activation
  • Enzyme Stability
  • Models, Chemical
  • Molecular Docking Simulation*
  • Multienzyme Complexes
  • Nucleotidyltransferases / chemistry*
  • Nucleotidyltransferases / ultrastructure*
  • Protein Binding
  • Protein Conformation
  • Ribonucleases / chemistry*
  • Ribonucleases / ultrastructure*
  • Staphylococcus epidermidis / enzymology*
  • Structure-Activity Relationship
  • Substrate Specificity

Substances

  • Multienzyme Complexes
  • Nucleotidyltransferases
  • polynucleotide pyrophosphorylase
  • Ribonucleases