Eukaryotic and archaeal DNA primase small subunit. DNA primase synthesises the RNA primers for the Okazaki fragments in lagging strand DNA synthesis. DNA primase is a heterodimer of large and small subunits. This family also includes baculovirus late expression factor 1 or LEF-1 proteins. Baculovirus LEF-1 is a DNA primase enzyme. Bacterial DNA primase adopts a different fold to archaeal and eukaryotic primases.