MTPAP

MTPAP is a member of the DNA polymerase type-B-like family. This enzyme synthesizes the 3' poly(A) tail of mitochondrial transcripts and plays a role in replication-dependent histone mRNA degradation.

Mitochondrial Poly(A) Polymerase

Polymerase that creates the 3' poly(A) tail of mitochondrial transcripts. Can use all four nucleotides, but has higher 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 before their degradation is initiated. Might be responsible for the creation of some UAA stop codons which are not encoded in mtDNA.

Histone mRNA catabolic process Source: UniProtKB
mRNA polyadenylation Source: UniProtKB
RNA 3'-end processing Source: GO_Central

Mitochondrion
Cytoplasm

Spastic ataxia 4, autosomal recessive (SPAX4):
A slowly progressive neurodegenerative disease characterized by cerebellar ataxia, spastic paraparesis, dysarthria, and optic atrophy.