This family consists of a novel motif designated as SERTA (for SEI-1, RBT1, and TARA), corresponding to the largest conserved region among TRIP-Br proteins [1]. The function of this motif is uncertain, but the CDK4-interacting segment of p34SEI-1 (amino acid residues 44-161) includes most of the SERTA motif [2].

1: The Drosophila gene taranis encodes a novel trithorax group member potentially linked to the cell cycle regulatory apparatus. Calgaro S, Boube M, Cribbs DL, Bourbon HM; Genetics 2002;160:547-560. PMID:11861561

2: Regulation of CDK4 activity by a novel CDK4-binding protein, p34(SEI-1). Sugimoto M, Nakamura T, Ohtani N, Hampson L, Hampson IN, Shimamoto A, Furuichi Y, Okumura K, Niwa S, Taya Y, Hara E; Genes Dev 1999;13:3027-3033. PMID:10580009