PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Nicotiana tomentosiformis
bHLH Family
Species TF ID Description
XP_009586806.1bHLH family protein
XP_009586991.1bHLH family protein
XP_009586992.1bHLH family protein
XP_009586993.1bHLH family protein
XP_009587041.1bHLH family protein
XP_009587187.1bHLH family protein
XP_009587237.1bHLH family protein
XP_009587243.1bHLH family protein
XP_009587276.1bHLH family protein
XP_009587651.1bHLH family protein
XP_009589122.1bHLH family protein
XP_009589214.1bHLH family protein
XP_009589864.1bHLH family protein
XP_009590362.1bHLH family protein
XP_009590627.1bHLH family protein
XP_009590631.1bHLH family protein
XP_009590632.1bHLH family protein
XP_009590633.1bHLH family protein
XP_009590722.1bHLH family protein
XP_009590723.1bHLH family protein
XP_009591015.1bHLH family protein
XP_009591142.1bHLH family protein
XP_009591238.1bHLH family protein
XP_009591240.1bHLH family protein
XP_009591396.1bHLH family protein
XP_009591424.1bHLH family protein
XP_009591427.1bHLH family protein
XP_009591471.1bHLH family protein
XP_009592282.1bHLH family protein
XP_009592394.1bHLH family protein
XP_009592395.1bHLH family protein
XP_009592416.1bHLH family protein
XP_009592442.1bHLH family protein
XP_009593502.1bHLH family protein
XP_009593503.1bHLH family protein
XP_009593504.1bHLH family protein
XP_009593799.1bHLH family protein
XP_009593800.1bHLH family protein
XP_009593801.1bHLH family protein
XP_009594399.1bHLH family protein
XP_009594402.1bHLH family protein
XP_009594403.1bHLH family protein
XP_009594425.1bHLH family protein
XP_009594550.1bHLH family protein
XP_009594724.1bHLH family protein
XP_009594725.1bHLH family protein
XP_009594726.1bHLH family protein
XP_009594832.1bHLH family protein
XP_009594898.1bHLH family protein
XP_009595347.1bHLH family protein
XP_009595499.1bHLH family protein
XP_009595500.1bHLH family protein
XP_009595501.1bHLH family protein
XP_009595524.1bHLH family protein
XP_009596056.1bHLH family protein
XP_009596776.1bHLH family protein
XP_009596972.1bHLH family protein
XP_009597068.1bHLH family protein
XP_009597069.1bHLH family protein
XP_009597248.1bHLH family protein
XP_009597249.1bHLH family protein
XP_009597290.1bHLH family protein
XP_009597422.1bHLH family protein
XP_009597633.1bHLH family protein
XP_009597785.1bHLH family protein
XP_009597786.1bHLH family protein
XP_009598406.1bHLH family protein
XP_009599119.1bHLH family protein
XP_009599823.1bHLH family protein
XP_009600065.1bHLH family protein
XP_009600066.1bHLH family protein
XP_009600067.1bHLH family protein
XP_009600068.1bHLH family protein
XP_009600069.1bHLH family protein
XP_009600070.1bHLH family protein
XP_009600071.1bHLH family protein
XP_009600422.1bHLH family protein
XP_009600874.1bHLH family protein
XP_009600953.1bHLH family protein
XP_009602073.1bHLH family protein
XP_009602074.1bHLH family protein
XP_009602075.1bHLH family protein
XP_009602076.1bHLH family protein
XP_009602077.1bHLH family protein
XP_009602219.1bHLH family protein
XP_009602346.1bHLH family protein
XP_009602354.1bHLH family protein
XP_009602360.1bHLH family protein
XP_009602367.1bHLH family protein
XP_009602423.1bHLH family protein
XP_009602440.1bHLH family protein
XP_009602728.1bHLH family protein
XP_009603227.1bHLH family protein
XP_009603228.1bHLH family protein
XP_009603358.1bHLH family protein
XP_009604694.1bHLH family protein
XP_009605333.1bHLH family protein
XP_009605433.1bHLH family protein
XP_009605673.1bHLH family protein
XP_009605674.1bHLH family protein
XP_009605832.1bHLH family protein
XP_009605833.1bHLH family protein
XP_009605955.1bHLH family protein
XP_009606580.1bHLH family protein
XP_009606816.1bHLH family protein
XP_009607290.1bHLH family protein
XP_009607578.1bHLH family protein
XP_009607579.1bHLH family protein
XP_009607890.1bHLH family protein
XP_009607891.1bHLH family protein
XP_009607937.1bHLH family protein
XP_009607938.1bHLH family protein
XP_009608011.1bHLH family protein
XP_009608279.1bHLH family protein
XP_009609287.1bHLH family protein
XP_009609302.1bHLH family protein
XP_009609911.1bHLH family protein
XP_009609942.1bHLH family protein
XP_009610531.1bHLH family protein
XP_009610672.1bHLH family protein
XP_009610673.1bHLH family protein
XP_009610749.1bHLH family protein
XP_009610959.1bHLH family protein
XP_009611307.1bHLH family protein
XP_009611349.1bHLH family protein
XP_009611733.1bHLH family protein
XP_009611734.1bHLH family protein
XP_009611804.1bHLH family protein
XP_009612393.1bHLH family protein
XP_009612610.1bHLH family protein
XP_009612697.1bHLH family protein
XP_009612854.1bHLH family protein
XP_009612855.1bHLH family protein
XP_009612948.1bHLH family protein
XP_009614250.1bHLH family protein
XP_009614307.1bHLH family protein
XP_009614938.1bHLH family protein
XP_009615362.1bHLH family protein
XP_009615601.1bHLH family protein
XP_009615802.1bHLH family protein
XP_009615803.1bHLH family protein
XP_009616456.1bHLH family protein
XP_009616457.1bHLH family protein
XP_009616536.1bHLH family protein
XP_009616537.1bHLH family protein
XP_009616538.1bHLH family protein
XP_009616540.1bHLH family protein
XP_009616651.1bHLH family protein
XP_009616821.1bHLH family protein
XP_009616845.1bHLH family protein
XP_009617115.1bHLH family protein
XP_009617116.1bHLH family protein
XP_009617136.1bHLH family protein
XP_009617148.1bHLH family protein
XP_009617305.1bHLH family protein
XP_009617474.1bHLH family protein
XP_009617734.1bHLH family protein
XP_009617831.1bHLH family protein
XP_009617897.1bHLH family protein
XP_009617979.1bHLH family protein
XP_009618593.1bHLH family protein
XP_009618594.1bHLH family protein
XP_009618595.1bHLH family protein
XP_009618665.1bHLH family protein
XP_009618756.1bHLH family protein
XP_009618779.1bHLH family protein
XP_009619149.1bHLH family protein
XP_009619169.1bHLH family protein
XP_009619568.1bHLH family protein
XP_009619569.1bHLH family protein
XP_009619774.1bHLH family protein
XP_009619775.1bHLH family protein
XP_009620076.1bHLH family protein
XP_009620077.1bHLH family protein
XP_009620310.1bHLH family protein
XP_009620411.1bHLH family protein
XP_009620426.1bHLH family protein
XP_009620427.1bHLH family protein
XP_009620567.1bHLH family protein
XP_009620568.1bHLH family protein
XP_009620570.1bHLH family protein
XP_009620571.1bHLH family protein
XP_009620738.1bHLH family protein
XP_009621297.1bHLH family protein
XP_009621298.1bHLH family protein
XP_009621466.1bHLH family protein
XP_009621535.1bHLH family protein
XP_009621536.1bHLH family protein
XP_009621537.1bHLH family protein
XP_009622200.1bHLH family protein
XP_009623441.1bHLH family protein
XP_009623534.1bHLH family protein
XP_009623539.1bHLH family protein
XP_009623659.1bHLH family protein
XP_009623662.1bHLH family protein
XP_009623788.1bHLH family protein
XP_009623799.1bHLH family protein
XP_009623949.1bHLH family protein
XP_009624214.1bHLH family protein
XP_009624505.1bHLH family protein
XP_009624511.1bHLH family protein
XP_009624514.1bHLH family protein
XP_009624565.1bHLH family protein
XP_009624566.1bHLH family protein
XP_009624713.1bHLH family protein
XP_009624714.1bHLH family protein
XP_009624851.1bHLH family protein
XP_009625133.1bHLH family protein
XP_009625228.1bHLH family protein
XP_009625368.1bHLH family protein
XP_009625856.1bHLH family protein
XP_009625857.1bHLH family protein
XP_009625858.1bHLH family protein
XP_009626236.1bHLH family protein
XP_009627192.1bHLH family protein
XP_009627197.1bHLH family protein
XP_009627204.1bHLH family protein
XP_009627217.1bHLH family protein
XP_009627647.1bHLH family protein
XP_009627739.1bHLH family protein
XP_009627868.1bHLH family protein
XP_009628050.1bHLH family protein
XP_009628051.1bHLH family protein
XP_009628530.1bHLH family protein
XP_009628531.1bHLH family protein
XP_009628533.1bHLH family protein
XP_009629262.1bHLH family protein
XP_009629598.1bHLH family protein
XP_009630063.1bHLH family protein
XP_009630109.1bHLH family protein
XP_009630429.1bHLH family protein
XP_009630561.1bHLH family protein
XP_009630765.1bHLH family protein
XP_009630766.1bHLH family protein
XP_009630767.1bHLH family protein
XP_009631087.1bHLH family protein
XP_009631088.1bHLH family protein
XP_009631111.1bHLH family protein
XP_009631112.1bHLH family protein
XP_009631535.1bHLH family protein
XP_009631846.1bHLH family protein
XP_009631983.1bHLH family protein
XP_009631984.1bHLH family protein
XP_009631985.1bHLH family protein
XP_009632043.1bHLH 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