PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Solanum pennellii
bHLH Family
Species TF ID Description
Sopen00g008050.1bHLH family protein
Sopen00g009860.1bHLH family protein
Sopen00g013410.1bHLH family protein
Sopen00g013520.1bHLH family protein
Sopen01g005670.1bHLH family protein
Sopen01g009900.1bHLH family protein
Sopen01g010070.1bHLH family protein
Sopen01g010120.1bHLH family protein
Sopen01g021920.1bHLH family protein
Sopen01g029220.1bHLH family protein
Sopen01g031830.1bHLH family protein
Sopen01g032700.1bHLH family protein
Sopen01g032710.1bHLH family protein
Sopen01g033890.1bHLH family protein
Sopen01g036520.1bHLH family protein
Sopen01g039770.1bHLH family protein
Sopen01g044750.1bHLH family protein
Sopen01g048830.1bHLH family protein
Sopen01g049400.1bHLH family protein
Sopen01g050130.1bHLH family protein
Sopen01g050140.1bHLH family protein
Sopen01g050150.1bHLH family protein
Sopen01g050170.1bHLH family protein
Sopen01g051890.1bHLH family protein
Sopen01g053190.1bHLH family protein
Sopen01g053190.2bHLH family protein
Sopen01g053190.3bHLH family protein
Sopen02g013710.1bHLH family protein
Sopen02g014520.1bHLH family protein
Sopen02g016520.1bHLH family protein
Sopen02g019960.1bHLH family protein
Sopen02g021850.1bHLH family protein
Sopen02g022960.1bHLH family protein
Sopen02g024530.1bHLH family protein
Sopen02g024580.1bHLH family protein
Sopen02g024720.1bHLH family protein
Sopen02g029550.1bHLH family protein
Sopen02g032580.1bHLH family protein
Sopen02g035600.1bHLH family protein
Sopen02g036060.1bHLH family protein
Sopen02g036300.1bHLH family protein
Sopen02g036380.1bHLH family protein
Sopen02g036390.1bHLH family protein
Sopen02g036390.2bHLH family protein
Sopen02g036400.1bHLH family protein
Sopen02g037840.1bHLH family protein
Sopen02g037840.2bHLH family protein
Sopen03g001390.1bHLH family protein
Sopen03g002910.1bHLH family protein
Sopen03g003370.1bHLH family protein
Sopen03g005340.1bHLH family protein
Sopen03g006760.1bHLH family protein
Sopen03g008590.1bHLH family protein
Sopen03g010770.1bHLH family protein
Sopen03g026080.1bHLH family protein
Sopen03g028560.1bHLH family protein
Sopen03g032060.1bHLH family protein
Sopen03g032600.1bHLH family protein
Sopen03g033330.1bHLH family protein
Sopen03g033800.1bHLH family protein
Sopen03g033800.2bHLH family protein
Sopen03g034530.1bHLH family protein
Sopen03g037210.1bHLH family protein
Sopen03g040050.1bHLH family protein
Sopen04g001150.1bHLH family protein
Sopen04g001150.2bHLH family protein
Sopen04g001200.1bHLH family protein
Sopen04g001260.1bHLH family protein
Sopen04g001710.1bHLH family protein
Sopen04g002080.1bHLH family protein
Sopen04g002360.1bHLH family protein
Sopen04g002500.1bHLH family protein
Sopen04g006480.1bHLH family protein
Sopen04g025470.1bHLH family protein
Sopen04g029770.1bHLH family protein
Sopen04g030550.1bHLH family protein
Sopen04g031080.1bHLH family protein
Sopen04g031550.1bHLH family protein
Sopen04g032290.1bHLH family protein
Sopen04g032390.1bHLH family protein
Sopen04g034300.1bHLH family protein
Sopen05g001310.1bHLH family protein
Sopen05g002590.1bHLH family protein
Sopen05g003170.1bHLH family protein
Sopen05g004940.1bHLH family protein
Sopen05g005450.1bHLH family protein
Sopen05g005680.1bHLH family protein
Sopen05g006420.1bHLH family protein
Sopen05g006570.1bHLH family protein
Sopen05g009670.1bHLH family protein
Sopen05g028990.1bHLH family protein
Sopen05g032160.1bHLH family protein
Sopen06g002870.1bHLH family protein
Sopen06g002870.2bHLH family protein
Sopen06g002870.3bHLH family protein
Sopen06g011230.1bHLH family protein
Sopen06g016530.1bHLH family protein
Sopen06g017200.1bHLH family protein
Sopen06g017530.1bHLH family protein
Sopen06g021950.1bHLH family protein
Sopen06g023060.1bHLH family protein
Sopen06g023550.1bHLH family protein
Sopen06g026160.1bHLH family protein
Sopen06g026630.1bHLH family protein
Sopen06g026900.1bHLH family protein
Sopen06g027190.1bHLH family protein
Sopen06g028890.1bHLH family protein
Sopen06g034560.1bHLH family protein
Sopen06g035370.1bHLH family protein
Sopen07g001380.1bHLH family protein
Sopen07g006930.1bHLH family protein
Sopen07g018910.1bHLH family protein
Sopen07g023150.1bHLH family protein
Sopen07g026270.1bHLH family protein
Sopen07g026480.1bHLH family protein
Sopen07g027250.1bHLH family protein
Sopen07g030480.1bHLH family protein
Sopen07g031930.1bHLH family protein
Sopen07g032180.1bHLH family protein
Sopen08g001070.1bHLH family protein
Sopen08g004440.1bHLH family protein
Sopen08g018260.1bHLH family protein
Sopen08g023720.1bHLH family protein
Sopen08g023740.1bHLH family protein
Sopen08g025340.1bHLH family protein
Sopen08g025500.1bHLH family protein
Sopen08g029440.1bHLH family protein
Sopen08g031370.1bHLH family protein
Sopen09g010690.1bHLH family protein
Sopen09g010770.1bHLH family protein
Sopen09g012960.1bHLH family protein
Sopen09g021180.1bHLH family protein
Sopen09g025180.1bHLH family protein
Sopen09g026630.1bHLH family protein
Sopen09g026820.1bHLH family protein
Sopen09g027610.1bHLH family protein
Sopen09g029650.1bHLH family protein
Sopen09g032140.1bHLH family protein
Sopen09g032280.1bHLH family protein
Sopen09g032810.1bHLH family protein
Sopen09g034650.1bHLH family protein
Sopen09g035810.1bHLH family protein
Sopen09g036050.1bHLH family protein
Sopen09g036050.2bHLH family protein
Sopen09g036050.3bHLH family protein
Sopen10g002460.1bHLH family protein
Sopen10g002570.1bHLH family protein
Sopen10g004110.1bHLH family protein
Sopen10g005050.1bHLH family protein
Sopen10g005070.1bHLH family protein
Sopen10g008180.1bHLH family protein
Sopen10g020610.1bHLH family protein
Sopen10g020770.1bHLH family protein
Sopen10g029040.1bHLH family protein
Sopen10g029690.1bHLH family protein
Sopen10g029710.1bHLH family protein
Sopen10g030290.1bHLH family protein
Sopen10g030300.1bHLH family protein
Sopen10g030300.2bHLH family protein
Sopen10g030310.1bHLH family protein
Sopen11g001740.1bHLH family protein
Sopen11g005120.1bHLH family protein
Sopen11g023410.1bHLH family protein
Sopen12g005040.1bHLH family protein
Sopen12g005590.1bHLH family protein
Sopen12g005590.2bHLH family protein
Sopen12g016990.1bHLH family protein
Sopen12g030120.1bHLH family protein
Sopen12g030120.2bHLH family protein
Sopen12g030360.1bHLH family protein
Sopen12g033380.1bHLH family protein
Sopen12g034770.1bHLH 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