Structure and mechanism of CutA, RNA nucleotidyl transferase with an unusual preference for cytosine.

ABSTRACT: Template-independent terminal ribonucleotide transferases (TENTs) catalyze the addition of nucleotide monophosphates to the 3'-end of RNA molecules regulating their fate. TENTs include poly(U) polymerases (PUPs) with a subgroup of 3' CUCU-tagging enzymes, such as CutA in Aspergillus nidulans. CutA preferentially incorporates cytosines, processively polymerizes only adenosines and does not incorporate or extend guanosines. The basis of this peculiar specificity remains to be established. Here, we describe crystal structures of the catalytic core of CutA in complex with an incoming non-hydrolyzable CTP analog and an RNA with three adenosines, along with biochemical characterization of the enzyme. The binding of GTP or a primer with terminal guanosine is predicted to induce clashes between 2-

SUBMITTER: Malik D 

PROVIDER: S-EPMC7498324 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature