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.
Original language | English (US) |
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Pages (from-to) | 2078-2084 |
Number of pages | 7 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 495 |
Issue number | 2 |
DOIs | |
State | Published - Jan 8 2018 |
Externally published | Yes |
Keywords
- Multi-protein assembly
- Phosphorolysis
- Polyadenylation
- RNA degradation
- Ribonuclease activity
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology