PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Citrus sinensis
bHLH Family
Species TF ID Description
orange1.1g004499mbHLH family protein
orange1.1g005019mbHLH family protein
orange1.1g005112mbHLH family protein
orange1.1g005651mbHLH family protein
orange1.1g006040mbHLH family protein
orange1.1g006142mbHLH family protein
orange1.1g006217mbHLH family protein
orange1.1g006283mbHLH family protein
orange1.1g006470mbHLH family protein
orange1.1g006479mbHLH family protein
orange1.1g007097mbHLH family protein
orange1.1g007258mbHLH family protein
orange1.1g007449mbHLH family protein
orange1.1g007527mbHLH family protein
orange1.1g007797mbHLH family protein
orange1.1g007974mbHLH family protein
orange1.1g008226mbHLH family protein
orange1.1g008631mbHLH family protein
orange1.1g008756mbHLH family protein
orange1.1g008874mbHLH family protein
orange1.1g008967mbHLH family protein
orange1.1g009521mbHLH family protein
orange1.1g009555mbHLH family protein
orange1.1g009564mbHLH family protein
orange1.1g009649mbHLH family protein
orange1.1g009659mbHLH family protein
orange1.1g009676mbHLH family protein
orange1.1g009904mbHLH family protein
orange1.1g010045mbHLH family protein
orange1.1g010053mbHLH family protein
orange1.1g010728mbHLH family protein
orange1.1g011193mbHLH family protein
orange1.1g011370mbHLH family protein
orange1.1g011373mbHLH family protein
orange1.1g011398mbHLH family protein
orange1.1g011621mbHLH family protein
orange1.1g012156mbHLH family protein
orange1.1g012160mbHLH family protein
orange1.1g012178mbHLH family protein
orange1.1g012246mbHLH family protein
orange1.1g012387mbHLH family protein
orange1.1g012640mbHLH family protein
orange1.1g013688mbHLH family protein
orange1.1g013752mbHLH family protein
orange1.1g014090mbHLH family protein
orange1.1g014374mbHLH family protein
orange1.1g014446mbHLH family protein
orange1.1g014477mbHLH family protein
orange1.1g014485mbHLH family protein
orange1.1g014506mbHLH family protein
orange1.1g014550mbHLH family protein
orange1.1g014958mbHLH family protein
orange1.1g015233mbHLH family protein
orange1.1g015330mbHLH family protein
orange1.1g015337mbHLH family protein
orange1.1g015380mbHLH family protein
orange1.1g015486mbHLH family protein
orange1.1g015571mbHLH family protein
orange1.1g015617mbHLH family protein
orange1.1g015639mbHLH family protein
orange1.1g015691mbHLH family protein
orange1.1g015848mbHLH family protein
orange1.1g016131mbHLH family protein
orange1.1g016577mbHLH family protein
orange1.1g016638mbHLH family protein
orange1.1g017062mbHLH family protein
orange1.1g017497mbHLH family protein
orange1.1g017583mbHLH family protein
orange1.1g017964mbHLH family protein
orange1.1g018007mbHLH family protein
orange1.1g018155mbHLH family protein
orange1.1g018789mbHLH family protein
orange1.1g018897mbHLH family protein
orange1.1g019338mbHLH family protein
orange1.1g019485mbHLH family protein
orange1.1g019508mbHLH family protein
orange1.1g019574mbHLH family protein
orange1.1g019597mbHLH family protein
orange1.1g019612mbHLH family protein
orange1.1g019617mbHLH family protein
orange1.1g019618mbHLH family protein
orange1.1g019625mbHLH family protein
orange1.1g019960mbHLH family protein
orange1.1g019974mbHLH family protein
orange1.1g020172mbHLH family protein
orange1.1g020210mbHLH family protein
orange1.1g020282mbHLH family protein
orange1.1g020455mbHLH family protein
orange1.1g020693mbHLH family protein
orange1.1g020774mbHLH family protein
orange1.1g020814mbHLH family protein
orange1.1g021208mbHLH family protein
orange1.1g021355mbHLH family protein
orange1.1g021729mbHLH family protein
orange1.1g022116mbHLH family protein
orange1.1g022171mbHLH family protein
orange1.1g022281mbHLH family protein
orange1.1g022288mbHLH family protein
orange1.1g022499mbHLH family protein
orange1.1g022649mbHLH family protein
orange1.1g022782mbHLH family protein
orange1.1g022809mbHLH family protein
orange1.1g023215mbHLH family protein
orange1.1g023629mbHLH family protein
orange1.1g023847mbHLH family protein
orange1.1g024111mbHLH family protein
orange1.1g024139mbHLH family protein
orange1.1g024231mbHLH family protein
orange1.1g024326mbHLH family protein
orange1.1g024344mbHLH family protein
orange1.1g024464mbHLH family protein
orange1.1g024653mbHLH family protein
orange1.1g024670mbHLH family protein
orange1.1g024930mbHLH family protein
orange1.1g025122mbHLH family protein
orange1.1g025407mbHLH family protein
orange1.1g025477mbHLH family protein
orange1.1g025665mbHLH family protein
orange1.1g025727mbHLH family protein
orange1.1g026390mbHLH family protein
orange1.1g026394mbHLH family protein
orange1.1g026436mbHLH family protein
orange1.1g026479mbHLH family protein
orange1.1g026599mbHLH family protein
orange1.1g026646mbHLH family protein
orange1.1g026702mbHLH family protein
orange1.1g026746mbHLH family protein
orange1.1g026943mbHLH family protein
orange1.1g027547mbHLH family protein
orange1.1g028060mbHLH family protein
orange1.1g028636mbHLH family protein
orange1.1g028999mbHLH family protein
orange1.1g029383mbHLH family protein
orange1.1g029713mbHLH family protein
orange1.1g029765mbHLH family protein
orange1.1g029776mbHLH family protein
orange1.1g030331mbHLH family protein
orange1.1g030782mbHLH family protein
orange1.1g032294mbHLH family protein
orange1.1g032295mbHLH family protein
orange1.1g032321mbHLH family protein
orange1.1g032324mbHLH family protein
orange1.1g035657mbHLH family protein
orange1.1g035883mbHLH family protein
orange1.1g036175mbHLH family protein
orange1.1g036406mbHLH family protein
orange1.1g036457mbHLH family protein
orange1.1g036531mbHLH family protein
orange1.1g036599mbHLH family protein
orange1.1g036669mbHLH family protein
orange1.1g036928mbHLH family protein
orange1.1g037136mbHLH family protein
orange1.1g037241mbHLH family protein
orange1.1g037441mbHLH family protein
orange1.1g037785mbHLH family protein
orange1.1g037798mbHLH family protein
orange1.1g037856mbHLH family protein
orange1.1g038084mbHLH family protein
orange1.1g038097mbHLH family protein
orange1.1g038298mbHLH family protein
orange1.1g038389mbHLH family protein
orange1.1g038451mbHLH family protein
orange1.1g038558mbHLH family protein
orange1.1g038918mbHLH family protein
orange1.1g039361mbHLH family protein
orange1.1g039443mbHLH family protein
orange1.1g039972mbHLH family protein
orange1.1g040019mbHLH family protein
orange1.1g040546mbHLH family protein
orange1.1g040760mbHLH family protein
orange1.1g041101mbHLH family protein
orange1.1g041198mbHLH family protein
orange1.1g041370mbHLH family protein
orange1.1g041818mbHLH family protein
orange1.1g042465mbHLH family protein
orange1.1g042649mbHLH family protein
orange1.1g042663mbHLH family protein
orange1.1g042904mbHLH family protein
orange1.1g042908mbHLH family protein
orange1.1g043072mbHLH family protein
orange1.1g043478mbHLH family protein
orange1.1g043618mbHLH family protein
orange1.1g043851mbHLH family protein
orange1.1g044343mbHLH family protein
orange1.1g044652mbHLH family protein
orange1.1g045155mbHLH family protein
orange1.1g045349mbHLH family protein
orange1.1g046178mbHLH family protein
orange1.1g047004mbHLH family protein
orange1.1g047562mbHLH family protein
orange1.1g047654mbHLH family protein
orange1.1g047850mbHLH family protein
orange1.1g048534mbHLH family protein
orange1.1g048817mbHLH family protein
bHLH Family Introduction

The basic/helix-loop-helix (bHLH) proteins are a superfamily of transcription factors that have been well characterized in nonplant eukaryotes, especially in mammalian systems, in which considerable structural, functional, and phylogenetic analyses have been performed. The data indicate that bHLH proteins are important regulatory components in transcriptional networks in these systems, controlling a diversity of processes from cell proliferation to cell lineage establishment.

This family is defined by the bHLH signature domain, which consists of 60 amino acids with two functionally distinct regions. The basic region, located at the N-terminal end of the domain, is involved in DNA binding and consists of 15 amino acids with a high number of basic residues. The HLH region, at the C-terminal end, functions as a dimerization domain and is constituted mainly of hydrophobic residues that form two amphipathic -helices separated by a loop region of variable sequence and length. Outside of the conserved bHLH domain, these proteins exhibit considerable sequence divergence. Cocrystal structural analysis has shown that the interaction between the HLH regions of two separate polypeptides leads to the formation of homodimers and/or heterodimers and that the basic region of each partner binds to half of the DNA recognition sequence. Some bHLH proteins form homodimers or restrict their heterodimerization activity to closely related members of the family. On the other hand, some can form heterodimers with one or several different partners.

The core DNA sequence motif recognized by the bHLH proteins is a consensus hexanucleotide sequence known as the E-box (5'-CANNTG-3'). There are different types of E-boxes, depending on the identity of the two central bases. One of the most common is the palindromic G-box (5'-CACGTG-3'). Certain conserved amino acids within the basic region of the protein provide recognition of the core consensus site, whereas other residues in the domain dictate specificity for a given type of E-box . In addition, flanking nucleotides outside of the hexanucleotide core have been shown to play a role in binding specificity, and there is evidence that a loop residue in the protein plays a role in DNA binding through elements that lie outside of the core recognition sequence.

Toledo-Ortiz G, Huq E, Quail PH.
The Arabidopsis basic/helix-loop-helix transcription factor family.
Plant Cell. 2003 Aug;15(8):1749-70
PMID: 12897250