Poly(A) RNA polymerase, mitochondrial (MTPAP)

Polymerase that produces the 3' poly(A) tail of mitochondrial transcripts. Can use all four nucleotides, but has greater activity with ATP and UTP (in vitro).

Plays a role in replication-dependent histone mRNA degradation. May be involved in the terminal uridylation of mature histone mRNAs until their degradation is initiated.