1RNI

Bifunctional DNA primase/polymerase domain of ORF904 from the archaeal plasmid pRN1

Summary for 1RNI

• Entry DOI: 10.2210/pdb1rni/pdb
• Related: 1RO0 1RO2
• Descriptor: ORF904, ZINC ION (3 entities in total)
• Functional Keywords: dna polymerase, primase, replication, polymerization, evolution of nucleic acid polymerizing enzymes
• Biological source: Sulfolobus islandicus
• Total number of polymer chains: 1
• Total formula weight: 25155.15

Authors

Lipps, G.,Weinzierl, A.O.,von Scheven, G.,Buchen, C.,Cramer, P. (deposition date: 2003-12-01, release date: 2004-01-27, Last modification date: 2024-10-16)

Primary citation

Lipps, G.,Weinzierl, A.O.,Von Scheven, G.,Buchen, C.,Cramer, P.
Structure of a bifunctional DNA primase-polymerase
Nat.Struct.Mol.Biol., 11:157-162, 2004

PubMed 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.

PubMed: 14730355
DOI: 10.1038/nsmb723

Experimental method

X-RAY DIFFRACTION (1.85 Å)