Plant Transcription Factor Database
Previous version: v3.0
Nicotiana tomentosiformis
SBP Family
Species TF ID Description
XP_009587225.1SBP family protein
XP_009592086.1SBP family protein
XP_009592087.1SBP family protein
XP_009593420.1SBP family protein
XP_009593422.1SBP family protein
XP_009593604.1SBP family protein
XP_009596192.1SBP family protein
XP_009596860.1SBP family protein
XP_009600444.1SBP family protein
XP_009600445.1SBP family protein
XP_009601043.1SBP family protein
XP_009602313.1SBP family protein
XP_009602314.1SBP family protein
XP_009607851.1SBP family protein
XP_009607852.1SBP family protein
XP_009607853.1SBP family protein
XP_009610112.1SBP family protein
XP_009612109.1SBP family protein
XP_009613083.1SBP family protein
XP_009613084.1SBP family protein
XP_009613085.1SBP family protein
XP_009613086.1SBP family protein
XP_009613087.1SBP family protein
XP_009613088.1SBP family protein
XP_009613089.1SBP family protein
XP_009613090.1SBP family protein
XP_009615765.1SBP family protein
XP_009615766.1SBP family protein
XP_009617528.1SBP family protein
XP_009617582.1SBP family protein
XP_009620386.1SBP family protein
XP_009620616.1SBP family protein
XP_009620617.1SBP family protein
XP_009620618.1SBP family protein
XP_009620619.1SBP family protein
XP_009620620.1SBP family protein
XP_009620621.1SBP family protein
XP_009621034.1SBP family protein
XP_009621035.1SBP family protein
XP_009621036.1SBP family protein
XP_009621037.1SBP family protein
XP_009621038.1SBP family protein
XP_009621039.1SBP family protein
XP_009622387.1SBP family protein
XP_009622640.1SBP family protein
XP_009622641.1SBP family protein
XP_009623325.1SBP family protein
XP_009625590.1SBP family protein
XP_009625591.1SBP family protein
XP_009625592.1SBP family protein
XP_009626190.1SBP family protein
XP_009627050.1SBP family protein
SBP Family Introduction

SQUAMOSA promoter binding proteins (SBPs) form a major family of plant-specific transcription factors related to flower development. Although SBPs are heterogeneous in primary structure, they share a highly conserved DNA-binding domain (DBD) that has been suggested to be zinc binding. Here we report the NMR solution structures of DBDs of two SBPs of Arabidopsis thaliana, SPL4 and SPL7. The two share essentially the same structural features. Each structure contains two zinc-binding sites consisting of eight Cys or His residues in a Cys3HisCys2HisCys or Cys6HisCys sequence motif in which the first four residues coordinate to one zinc and the last four coordinate to the other. These structures are dissimilar to other known zinc-binding structures, and thus represent a novel type of zinc-binding motif. The electrostatic profile on the surface suggested that a continuous region, including all the conserved basic residues, is involved in the DNA binding, the mode of which is likely to be novel as well.

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.
A novel zinc-binding motif revealed by solution structures of DNA-binding domains of Arabidopsis SBP-family transcription factors
J Mol Biol. 2004 Mar 12;337(1):49-63.
PMID: 15001351

SBP-box genes were first characterized as SQUAMOSA promoter binding proteins (SBPs) to regulate the expression of MADS-box genes in early flower development of A. majus (Klein et al., 1996). Since then, SBP-box genes have been identified in many plants including green alga, moss, silver birch, A. majus, Arabidopsis and maize. They play critical roles in regulating flower and fruit development as well as other physiological processes ([Moreno et al., 1997],[Eriksson et al., 2004], [Lannenpaa et al., 2004], [Arazi et al., 2005] and [Kropat et al., 2005]). It has been reported that Arabidopsis SPL3, SPL8 and SPL14 involves in flowering, sporogenesis, GA signaling and toxin resistance ([Cardon et al., 1997], [Unte et al., 2003], [Stone et al., 2005] and [Zhang et al., 2006]) while maize tga1 and tomato LeSPL-CNR affect fruit development ([Wang et al., 2005a] and [Manning et al., 2006]).

SBP-box genes encode proteins sharing a conserved DNA-binding domain of 79 amino acid residues. It has been proved that the DNA-binding domain of SBP-box genes is necessary and sufficient to bind to a palindromic GTAC core motif ([Klein et al., 1996], [Cardon et al., 1997], [Cardon et al., 1999], [Lannenpaa et al., 2004] and [Birkenbihl et al., 2005]). Studies on the NMR solution structure of the fragment of Arabidopsis SPL4 and SPL7 revealed that the DNA-binding domain of SBPs consisted of two separate zinc-binding sites. One zinc finger is C3H or C4 and the other is C2HC (Yamasaki et al., 2004 K. Yamasaki et al.,).

Guo AY, Zhu QH, Gu X, Ge S, Yang J, Luo J.
Genome-wide identification and evolutionary analysis of the plant specific SBP-box transcription factor family.
Gene. 2008 Jul 15;418(1-2):1-8.
PMID: 18495384