The archaeo-eukaryotic GINS proteins and the archaeal primase catalytic subunit PriS share a common domain

Agnieszka Swiatek,Stuart A Macneill

doi:10.1186/1745-6150-5-17

Abstract

Primase and GINS are essential factors for chromosomal DNA replication in eukaryotic and archaeal cells. Here we describe a previously undetected relationship between the C-terminal domain of the catalytic subunit (PriS) of archaeal primase and the B-domains of the archaeo-eukaryotic GINS proteins in the form of a conserved structural domain comprising a three-stranded antiparallel β-sheet adjacent to an α-helix and a two-stranded β-sheet or hairpin. The presence of a shared domain in archaeal PriS and GINS proteins, the genes for which are often found adjacent on the chromosome, suggests simple mechanisms for the evolution of these proteins.ReviewersThis article was reviewed by Zvi Kelman (nominated by Michael Galperin) and Kira Makarova.

Highlights

Structural similarities between the primase subunit (PriS) C-terminal domain (CTD) and B-domains of Sld5, Psf2 and Psf3 were readily identified, with Z-scores of 5.6, 5.5 and 3.4 and rmsd values of 2.6, 2.6 and 1.9 Å for 50, 48 and 38 Cα atoms, Figure 1 Multiple sequence alignment of archaeal primase CTDs and archaeal and eukaryotic GINS B-domains
Primases are specialised DNA-dependent RNA polymerase enzymes that function in chromosome replication to synthesise oligoribonucleotide primers for use by the replicative DNA polymerases [1,2]
The second class are the heterodimeric primases of the archaeoeukaryotic primase (AEP) superfamily found in the eukarya and archaea but which are present in some bacteria [3]

Summary

Introduction

Structural similarities between the PriS CTD and B-domains of Sld5, Psf2 and Psf3 were readily identified, with Z-scores of 5.6, 5.5 and 3.4 and rmsd values of 2.6, 2.6 and 1.9 Å for 50, 48 and 38 Cα atoms, Figure 1 Multiple sequence alignment of archaeal primase CTDs and archaeal and eukaryotic GINS B-domains.

Results

Conclusion