PAP-associated domain-containing protein 5; topoisomerase-related function protein 4-2; TRF4-2 (PAPD5)

Function

• catalytic subunit of a TRAMP-like complex
  • poly(A) RNA polymerase activity
  • originally thought to have DNA polymerase activity
• role in post-transcriptional quality control mechanism
• polyadenylation with short oligo(A) tails is required for degradative activity of the exosome on several of its nuclear RNA substrates
• no cofactor for polyadenylation activity needed (in vitro).
• role in replication-dependent histone mRNA degradation
• may be involved in the terminal uridylation of mature histone mRNAs before their degradation is initiated
• may play a role in sister chromatid cohesion

deoxynucleoside triphosphate + DNA(n)  <-->
                             diphosphate + DNA(n+1)

Cofactor: Mg+2 or Mn+2 (putative)

Structure

• belongs to the DNA polymerase type-B-like family
• contains 1 PAP-associated domain

Compartment

• nucleus, cytoplasm
• predominantly expressed in the cytoplasm

Alternative splicing

named isoforms=5

Notes

• originally thought to have DNA polymerase activity

More general terms

• DNA polymerase
• phosphoprotein
• human longevity protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=64282
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:64282
• OMIM: https://mirror.omim.org/entry/605540
• UniProt: http://www.uniprot.org/uniprot/Q8NDF8.html