Description

IPR022312 is a DNA polymerase family X.

<p>Family X DNA polymerases (PolX) are involved in DNA repair, being evolutionarily conserved in prokaryotes, eukaryotes and archaea. All DNA polymerases from this family are single-subunit enzymes, lacking the 3'-5' exonuclease activity and displaying very low processivity during primer extension reactions [[cite:PUB00097985]]. Proteins in this family include in the well-characterized mammalian Pol beta; more recently discovered eukaryotic polymerases lambda, and mu; and a template-independent polymerase, terminal transferase (TdT) [[cite:PUB00097986]].</p> <p>DNA carries the biological information 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 3'-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. Three motifs, A, B and C [[cite:PUB00004955]], 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 (Escherichia coli) structure: motif A contains a strictly-conserved aspartate at the junction of a β-strand and an α-helix; motif B contains an α-helix with positive charges; and motif C has a doublet of negative charges, located in a β-turn-β secondary structure [[cite:PUB00004955]].</p> <p>DNA polymerases ([ec:2.7.7.7]) can be classified, on the basis of sequence similarity [[cite:PUB00004647], [cite:PUB00004955]], into at least four different groups: A, B, C and X. Members of family X are small (about 40kDa) compared with other polymerases and encompass two distinct polymerase enzymes that have similar functionality: vertebrate polymerase beta (same as yeast pol 4), and terminal deoxynucleotidyl-transferase (TdT) ([ec:2.7.7.31]). The former functions in DNA repair, while the latter terminally adds single nucleotides to polydeoxynucleotide chains. Both enzymes catalyse addition of nucleotides in a distributive manner, i.e. they dissociate from the template-primer after addition of each nucleotide. DNA-polymerases show a degree of structural similarity with RNA-polymerases.</p>

This description is obtained from EB-eye REST.

Associated GO terms

GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on April 27, 2020, while the GO metadata was last updated on April 27, 2020.

Associated Lotus transcripts 5

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: