This domain is found at the C-terminal end of DNA polymerase alpha- binding protein Ctf4 from yeast, its human orthologue AND1, and similar proteins from eukaryotes. This accessory factor for DNA replication plays a role in accurately duplicating the genome in vivo. This domain folds into a helical extension that is linked to the beta-propeller domain (Pfam:PF12341) and protrudes from one face of the disk-shaped trimer formed by the protein. It is essential for binding of dynamic partner proteins, such as Pol alpha-primase [1-4].

1: A Ctf4 trimer couples the CMG helicase to DNA polymerase alpha in the eukaryotic replisome. Simon AC, Zhou JC, Perera RL, van Deursen F, Evrin C, Ivanova ME, Kilkenny ML, Renault L, Kjaer S, Matak-Vinkovic D, Labib K, Costa A, Pellegrini L; Nature. 2014;510:293-297. PMID:24805245

2: The structure and polymerase-recognition mechanism of the crucial adaptor protein AND-1 in the human replisome. Guan C, Li J, Sun D, Liu Y, Liang H; J Biol Chem. 2017;292:9627-9636. PMID:28381552

3: The human CTF4-orthologue AND-1 interacts with DNA polymerase alpha/primase via its unique C-terminal HMG box. Kilkenny ML, Simon AC, Mainwaring J, Wirthensohn D, Holzer S, Pellegrini L; Open Biol. 2017; [Epub ahead of print] PMID:29167311

4: Ctf4 organizes sister replisomes and Pol alpha into a replication factory. Yuan Z, Georgescu R, Santos RLA, Zhang D, Bai L, Yao NY, Zhao G, O'Donnell ME, Li H; Elife. 2019; [Epub ahead of print] PMID:31589141