Family

DNA-directed DNA-polymerase, family A, mitochondria (IPR002297)

Short name: DNA-dir_DNA_pol_A_mt

Family relationships

Description

DNA carries the biological informatio`n that instructs cells how to exist in an ordered fashion. Accurate replication is thus one of the most important events in the cell life cycle. This function is mediated by DNA-directed DNA-polymerases, which add nucleotide triphosphate (dNTP) residues to the 5'-end of the growing DNA chain, using a complementary DNA as template. Small RNA molecules are generally used as primers for chain elongation, although terminal proteins may also be used. DNA-dependent DNA-polymerases have been grouped into families, denoted A, B and X, on the basis of sequence similarities [PMID: 3479792, PMID: 2196557]. Members of family A, which includes bacterial and bacteriophage polymerases, share significant similarity to Escherichia coli polymerase I; hence family A is also known as the pol I family. The bacterial polymerases also contain an exonuclease activity, which is coded for in the N-terminal portion. The yeast gamma polymerases show some similarity to the prokaryotic nuclear polymerases of family A, but their function is restricted to mitochondrial DNA replication and repair [PMID: 3522588]. Three motifs, A, B and C [PMID: 2196557], are seen to be conserved across all DNA-polymerases, with motifs A and C also seen in RNA- polymerases. They are centred on invariant residues, and their structural significance was implied from the Klenow (E. coli) structure. Motif A contains a strictly-conserved aspartate at the junction of a beta-strand and an alpha-helix; motif B contains an alpha-helix with positive charges; and motif C has a doublet of negative charges, located in a beta-turn-beta secondary structure [PMID: 2196557].

GO terms

Biological Process

GO:0006260 DNA replication

Molecular Function

GO:0003677 DNA binding

Cellular Component

GO:0005760 gamma DNA polymerase complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PRINTS
PANTHER