Bacterial DnaG primase, TOPRIM domain (IPR034151)

Short name: TOPRIM_DnaG_bac

Overlapping homologous superfamilies


Domain relationships

  • TOPRIM domain (IPR006171)
    • Bacterial DnaG primase, TOPRIM domain (IPR034151)


This topoisomerase-primase (TORPIM) nucleotidyl transferase/hydrolase domain is found in proteins similar to Escherichia coli DnaG. The active site of the primase is located within the TOPRIM domain [PMID: 10873470]. Primases synthesize RNA primers for the initiation of DNA replication. DnaG type primases are often closely associated with DNA helicases in primosome assemblies [PMID: 10873470].

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. E. coli DnaG is a single subunit enzyme [PMID: 9722641].

Contributing signatures

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