NAD⁺-dependent RNA terminal 2' and 3' phosphomonoesterase activity of a subset of Tpt1 enzymes.

ABSTRACT: The enzyme Tpt1 removes the 2'-PO₄ at the splice junction generated by fungal tRNA ligase; it does so via a two-step reaction in which (i) the internal RNA 2'-PO₄ attacks NAD⁺ to form an RNA-2'-phospho-ADP-ribosyl intermediate; and (ii) transesterification of the ribose O2″ to the 2'-phosphodiester yields 2'-OH RNA and ADP-ribose-1″,2″-cyclic phosphate products. The role that Tpt1 enzymes play in taxa that have no fungal-type RNA ligase remains obscure. An attractive prospect is that Tpt1 enzymes might catalyze reactions other than internal RNA 2'-PO₄ removal, via their unique NAD⁺-dependent transferase mechanism. This study extends the repertoire of the Tpt1 enzyme family to include the NAD⁺-dependent conversion of RNA term

SUBMITTER: Munir A 

PROVIDER: S-EPMC6573784 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature