Function
Zinc phosphodiesterase, which has both exoribonuclease and endoribonuclease activities, depending on the nature of the substrate and of the added divalent cation, and on its 3'-terminal structure. Can process the 3' termini of both CCA-less and CCA-containing tRNA precursors. CCA-less tRNAs are cleaved endonucleolytically after the discriminator base, whereas residues following the CCA sequence can be removed exonucleolytically or endonucleolytically in CCA-containing molecules. Does not remove the CCA sequence. May also be involved in the degradation of mRNAs. In vitro, hydrolyzes bis(p-nitrophenyl)phosphate and thymidine-5'-p-nitrophenyl phosphate.
Sequence
MELIFLGTSAGVPTRTRNVTAILLNLQHPTQSGLWLFDCGEGTQHQLLHTAFNPGKLDKIFISHLHGDHLFGLPGLLCSRSMSGIIQPLTIYGPQGIREFVETALRISGSWTDYPLEIVEIGAGEILDDGLRKVTAYPLEHPLECYGYRIEEHDKPGALNAQALKAAGVPPGPLFQELKAGKTITLEDGRQINGADYLAAPVPGKALAIFGDTGPCDAALDLAKGVDVMVHEATLDITMEAKANSRGHSSTRQAATLAREAGVGKLIITHVSSRYDDKGCQHLLRECRSIFPATELANDFTVFNV