Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 11 (2), 157-62

Structure of a Bifunctional DNA Primase-Polymerase

Affiliations

Structure of a Bifunctional DNA Primase-Polymerase

Georg Lipps et al. Nat Struct Mol Biol.

Abstract

Genome replication generally requires primases, which synthesize an initial oligonucleotide primer, and DNA polymerases, which elongate the primer. Primase and DNA polymerase activities are combined, however, in newly identified replicases from archaeal plasmids, such as pRN1 from Sulfolobus islandicus. Here we present a structure-function analysis of the pRN1 primase-polymerase (prim-pol) domain. The crystal structure shows a central depression lined by conserved residues. Mutations on one side of the depression reduce DNA affinity. On the opposite side of the depression cluster three acidic residues and a histidine, which are required for primase and DNA polymerase activity. One acidic residue binds a manganese ion, suggestive of a metal-dependent catalytic mechanism. The structure does not show any similarity to DNA polymerases, but is distantly related to archaeal and eukaryotic primases, with corresponding active-site residues. We propose that archaeal and eukaryotic primases and the prim-pol domain have a common evolutionary ancestor, a bifunctional replicase for small DNA genomes.

Similar articles

See all similar articles

Cited by 47 PubMed Central articles

See all "Cited by" articles

Publication types

LinkOut - more resources

Feedback