An iron-sulfur domain of the eukaryotic primase is essential for RNA primer synthesis

Primases synthesize the RNA primers that are necessary for replication of the parental DNA strands. Here we report that the heterodimeric archaeal/ eukaryotic primase is an iron- sulfur ( Fe- S) protein. Binding of the Fe- S cluster is mediated by an evolutionarily conserved domain at the C terminus of the large subunit. We further show that the Fe- S domain is essential to the unique ability of the eukaryotic primase to start DNA replication.