Domain

Archaeal primase DnaG/twinkle, TOPRIM domain (IPR034154)

Short name: TOPRIM_DnaG/twinkle

Overlapping homologous superfamilies

None.

Domain relationships

None.

Description

This topoisomerase-primase (TOPRIM) nucleotidyl transferase/hydrolase domain is found in archaeal DnaG-type primases and in mitochondrial twinkle helicase. In archaea, DnaG is tightly associated with the RNA-degrading exosome [PMID: 24789718, PMID: 23324612]. DnaG of Sulfolobus solfataricus has been shown to exhibit primase activity in vitro [PMID: 20122937]. Twinkle is needed for mitochondrial DNA replication and may be involved in recombinational repair of mitochondrial DNA [PMID: 26887820].

The TOPRIM domain has two conserved motifs, one of which centres at a conserved glutamate and the other one at two conserved aspartates (DxD). This glutamate and two aspartates, cluster together to form a highly acid surface patch. The conserved glutamate may act as a general base in nucleotide polymerization by primases. The DXD motif may co-ordinate Mg2+, a cofactor required for full catalytic function [PMID: 9722641].

Contributing signatures

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