Polynucleotide adenylyltransferase

Human genes with this activity include TUT1, MTPAP, PAPOLA, PAPOLB, PAPOLG, TENT2, TENT4A, TENT4B, TENT5C, TENT5D.

This enzyme is responsible for the addition of the 3' polyadenine tail to a newly synthesized pre-messenger RNA (pre-mRNA) molecule during the process of gene transcription.

After cleavage of the 3' signaling region that directs the assembly of the complex, polyadenylate polymerase (PAP) adds the polyadenine tail to the new 3' end.

PAP is phosphorylated by mitosis-promoting factor, a key regulator of the cell cycle.

As of late 2007, 27 structures have been solved for this class of enzymes, with PDB accession codes 1AV6, 1B42, 1BKY, 1EAM, 1EQA, 1F5A, 1FA0, 1JSZ, 1JTE, 1JTF, 1P39, 1Q78, 1Q79, 1V39, 1VFG, 1VP3, 1VP9, 1VPT, 2GA9, 2GAF, 2HHP, 2O1P, 2Q66, 2VP3, 3MAG, 3MCT, and 4DCG.

Structure of E. coli poly(A) polymerase based on PDB 3AQN. Missing segments were reconstructed using MODELLER. Rendered using ChimeraX.