beta-strand (B) domain of GINS complex protein Psf3
Psf3 (partner of Sld5 3) is one of the proteins known to comprise the GINS (named from the Japanese go-ichi-ni-san, meaning 5-1-2-3 for the Sld5, Psf1, Psf2, and Psf3 subunits) complex, which is a macromolecular protein complex associated with DNA replication. Psf3 is dysregulated in cancer cells, and its overexpression may be related to tumor progression in some cancers including colon, breast, and lung cancers; its expression can be used as a prognostic indicator in some cancers. GINS is a complex of four subunits (Sld5, Psf1, Psf2 and Psf3) that is involved in both the initiation and elongation stages of eukaryotic chromosome replication. Besides being essential for the maintenance of genomic integrity, GINS plays a central role in coordinating DNA replication with cell cycle checkpoints and is involved in cell growth. The eukaryotic GINS subunits Sld5, Psf1, Psf2, and Psf3 are homologous, and homologs are also found in archaea; the complex is not found in bacteria. The four subunits of the complex consist of two domains each, called the alpha-helical (A) and beta-strand (B) domains. The A and B domains of Sld5/Psf1 are permuted with respect to Psf1/Psf3. This model represents the B-domain of GINS subunit Psf3.
Structure:2Q9Q, human GINS subunit Psf3 interface with other subunits in the heterotetramer; contacts at 4A - View structure with Cn3D
Comment:the GINS complex contains four subunits: Sld5, Psf1, Psf2, and Psf3; it functions as a tight heterotetrameric complex in which major interactions are mediated through helix-helix interactions that amplify the helix-bundle-like structure of each individual subunit
Jiyao W et al.(2023). "The conserved domain database in 2023.",