Squamosa promoter binding protein explained

Symbol:	SBP
SBP
Pfam:	PF03110
Interpro:	IPR004333
Prosite:	PDOC00798
Scop:	2lao
Tcdb:	3.A.1

The SQUAMOSA promoter binding protein-like (SBP or SPL) family of transcription factors are defined by a plant-specific DNA-binding domain. The founding member of the family was identified based on its specific in vitro binding to the promoter of the snapdragon SQUAMOSA gene.^[1] SBP proteins are thought to be transcriptional activators.

Function

SPB proteins have roles in leaf development, vegetative phase change, flower and fruit development, plant architecture, sporogenesis, Gibberelic acid signaling and toxin response.^[2]

Structure

The domain contains 10 conserved cysteine and histidine residues that probably are zinc ligands.The SBP domain is a highly conserved DNA-binding domain. It is approximately 80 amino acids in length and contains a zinc finger motifwith two zinc-binding sites: Cys-Cys-His-Cys and Cys-Cys-Cys-His. It has a three-stranded antiparallel beta-sheet.^[3]

External links

SBP family at PlantTFDB: Plant Transcription Factor Database

Notes and References

Klein J, Saedler H, Huijser P . A new family of DNA binding proteins includes putative transcriptional regulators of the Antirrhinum majus floral meristem identity gene SQUAMOSA . Mol. Gen. Genet. . 250 . 1 . 7–16 . January 1996 . 8569690 . 10.1007/bf02191820. 20915344 .
Chen X, Zhang Z, Liu D, Zhang K, Li A, Mao L . SQUAMOSA promoter-binding protein-like transcription factors: star players for plant growth and development. . Journal of Integrative Plant Biology . 2010 . 52 . 11 . 946–51 . 20977652 . 10.1111/j.1744-7909.2010.00987.x .
Yamasaki K, Kigawa T, Inoue M, Tateno M, Yamasaki T, Yabuki T, etal . A novel zinc-binding motif revealed by solution structures of DNA-binding domains of Arabidopsis SBP-family transcription factors. . J Mol Biol . 2004 . 337 . 1 . 49–63 . 15001351 . 10.1016/j.jmb.2004.01.015 .