Plant Transcription Factor Database
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Citrus sinensis
SBP Family
Species TF ID Description
orange1.1g001315mSBP family protein
orange1.1g001317mSBP family protein
orange1.1g001453mSBP family protein
orange1.1g001971mSBP family protein
orange1.1g002028mSBP family protein
orange1.1g002122mSBP family protein
orange1.1g002868mSBP family protein
orange1.1g002916mSBP family protein
orange1.1g002919mSBP family protein
orange1.1g002922mSBP family protein
orange1.1g003063mSBP family protein
orange1.1g003138mSBP family protein
orange1.1g003787mSBP family protein
orange1.1g004030mSBP family protein
orange1.1g004062mSBP family protein
orange1.1g004091mSBP family protein
orange1.1g004246mSBP family protein
orange1.1g005162mSBP family protein
orange1.1g005929mSBP family protein
orange1.1g006174mSBP family protein
orange1.1g006595mSBP family protein
orange1.1g006602mSBP family protein
orange1.1g007712mSBP family protein
orange1.1g007870mSBP family protein
orange1.1g007883mSBP family protein
orange1.1g008080mSBP family protein
orange1.1g008680mSBP family protein
orange1.1g008770mSBP family protein
orange1.1g008776mSBP family protein
orange1.1g009653mSBP family protein
orange1.1g010591mSBP family protein
orange1.1g010605mSBP family protein
orange1.1g010621mSBP family protein
orange1.1g010865mSBP family protein
orange1.1g010873mSBP family protein
orange1.1g011635mSBP family protein
orange1.1g011637mSBP family protein
orange1.1g011640mSBP family protein
orange1.1g011646mSBP family protein
orange1.1g011651mSBP family protein
orange1.1g011662mSBP family protein
orange1.1g013094mSBP family protein
orange1.1g016364mSBP family protein
orange1.1g016391mSBP family protein
orange1.1g016971mSBP family protein
orange1.1g017206mSBP family protein
orange1.1g017207mSBP family protein
orange1.1g017256mSBP family protein
orange1.1g017311mSBP family protein
orange1.1g020302mSBP family protein
orange1.1g021420mSBP family protein
orange1.1g023467mSBP family protein
orange1.1g026888mSBP family protein
orange1.1g029650mSBP family protein
orange1.1g030599mSBP family protein
orange1.1g032310mSBP family protein
orange1.1g032937mSBP family protein
orange1.1g046416mSBP 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