Poly(A)-specific ribonuclease (PARN) loses specificity for recognition of adenosine residues in the presence of Mn2+
(English)Manuscript (Other academic)
Poly(A)-specific ribonuclease (PARN) is an oligomeric, processive and cap-interacting 3'-5' exoribonuclease that efficiently degrades eukaryotic mRNA poly(A) tails. PARN is a member of the DEDD superfamily of exonucleases and is dependent on divalent metal ions for its activity. Here, we have investigated how PARN poly(A) specificity can be modulated by using Mn2+ instead of Mg2+ as the divalent metal ion. In the presence of Mn2+ PARN lost specificity for poly(A) degradation. By using homotrinucleotides as substrates we could demonstrate that the loss in specificity was an intrinsic property of the active site in the presence of Mn2+ and not caused by changes in the RNA binding properties of PARN. We conclude that Mn2+ can be used as a probe to understand mechanisms behind poly(A) specificity in the active site of PARN.
mRNA degradation, deadenylation, Poly (A)-specific ribonuclease, active site, poly(A)-specificity, Mn2+
IdentifiersURN: urn:nbn:se:uu:diva-100497OAI: oai:DiVA.org:uu-100497DiVA: diva2:210384