SBP domains (for SQUAMOSA-pROMOTER BINDING PROTEIN) are found in plant proteins. It is a sequence specific DNA-binding domain [1]. Members of family probably function as transcription factors involved in the control of early flower development [1]. The domain contains 10 conserved cysteine and histidine residues that probably are zinc ligands.

1: A new family of DNA binding proteins includes putative transcriptional regulators of the Antirrhinum majus floral meristem identity gene SQUAMOSA. Klein J, Saedler H, Huijser P; Mol Gen Genet 1996;250:7-16. PMID:8569690

2: A novel zinc-binding motif revealed by solution structures of DNA-binding domains of Arabidopsis SBP-family transcription factors. Yamasaki K, Kigawa T, Inoue M, Tateno M, Yamasaki T, Yabuki T, Aoki M, Seki E, Matsuda T, Nunokawa E, Ishizuka Y, Terada T, Shirouzu M, Osanai T, Tanaka A, Seki M, Shinozaki K, Yokoyama S; J Mol Biol 2004;337:49-63. PMID:15001351