The initiation of eukaryotic chromosomal DNA replication requires the formation of an active replicative helicase at the replication origins of chromosomes. Yeast Sld3 and its metazoan counterpart treslin are the hub proteins mediating protein associations critical for formation of the helicase. The Sld7 protein interacts with Sld3, and the complex formed is thought to regulate the function of Sld3. Although Sld7 is a non-essential DNA replication protein that is found in only a limited range of yeasts, its depletion slowed the growth of cells and caused a delay in the S phase. Structure analysis indicates that the N-terminal domain of Sld7 binds to the N-terminal region of Sld3 [1].

1: The quaternary structure of the eukaryotic DNA replication proteins Sld7 and Sld3. Itou H, Shirakihara Y, Araki H; Acta Crystallogr D Biol Crystallogr. 2015;71:1649-1656. PMID:26249346