diphosphoinositol polyphosphate phosphohydrolase NUDT4B; DIPP-2B; nucleoside diphosphate-linked moiety X motif 4B; Nudix motif 4B; Nudix hydrolase 4B (NUDT4B)

Function

• cleaves a beta-phosphate from the diphosphate groups in PPinsP5 (diphosphoinositol pentakisphosphate), PP-insP4 & [PP]2-insP4 (bisdiphosphoinositol tetrakisphosphate), suggesting that it may play a role in signal transduction
• able to catalyze the hydrolysis of dinucleoside oligophosphate Ap6A
  • major reaction products are ADP & p4a from Ap6A
• does not catalyze hydrolysis of Ap5A.
• also able to hydrolyze 5-phosphoribose 1-diphosphate
• does not play a role in U8 snoRNA decapping activity
• binds U8 snoRNA

Cofactor:

• Mg+2, Mn+2
• binds 3 Mg+2 or Mn+2 ions per subunit

diphospho-myo-inositol polyphosphate + H2O = myo-inositol polyphosphate + phosphate

Structure

belongs to the Nudix hydrolase family, DIPP subfamily

Compartment

cytoplasm

More general terms

• nucleoside diphosphate-linked moiety X motif

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=11163
• UniProt: http://www.uniprot.org/uniprot/A0A024RBG1.html