Decapping & exoribonuclease protein; DXO; dom-3 homolog Z (DXO, DOM3L, DOM3Z, NG6)

Function

• ribonuclease that specifically degrades pre-mRNAs with a defective 5' end cap & is part of a pre-mRNA capping quality control
• has decapping, pyrophosphohydrolase & 5'-3' exonuclease activities
• has decapping activity toward incomplete 5' end cap mRNAs such as unmethylated 5' end-capped RNA to release GpppN & 5' end monophosphate RNA*
  • the 5' end monophosphate RNA is then degraded by the 5'-3' exoribonuclease activity, enabling this enzyme to decap & degrade incompletely capped mRNAs
• also possesses RNA 5'-pyrophosphohydrolase activity by hydrolyzing the 5' end triphosphate to release pyrophosphates (putative)

Cofactor: binds 2 Mg+2 (putative)

* this is in contrast to canonical decapping enzymes DCP2 & NUDT16, which release m(7)pppG (m(7)GDP)

Structure

belongs to the DXO/dom3Z family

Compartment

nucleus

Expression

ubiquitously expressed

More general terms

• exoribonuclease
• nuclear protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=1797
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1797
• OMIM: https://mirror.omim.org/entry/605996
• UniProt: http://www.uniprot.org/uniprot/O77932.html