This family contains the eukaryotic protein geminin (approximately 200 residues long). Geminin inhibits DNA replication by preventing the incorporation of MCM complex into prereplication complex, and is degraded during the mitotic phase of the cell cycle. It has been proposed that geminin inhibits DNA replication during S, G2, and M phases and that geminin destruction at the metaphase-anaphase transition permits replication in the succeeding cell cycle [1].

1: Geminin, an inhibitor of DNA replication, is degraded during mitosis. McGarry TJ, Kirschner MW; Cell 1998;93:1043-1053. PMID:9635433