PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Nicotiana sylvestris
bHLH Family
Species TF ID Description
XP_009757518.1bHLH family protein
XP_009757519.1bHLH family protein
XP_009757584.1bHLH family protein
XP_009757585.1bHLH family protein
XP_009757586.1bHLH family protein
XP_009757612.1bHLH family protein
XP_009757613.1bHLH family protein
XP_009757642.1bHLH family protein
XP_009757727.1bHLH family protein
XP_009757856.1bHLH family protein
XP_009758713.1bHLH family protein
XP_009758954.1bHLH family protein
XP_009758955.1bHLH family protein
XP_009758957.1bHLH family protein
XP_009758958.1bHLH family protein
XP_009758959.1bHLH family protein
XP_009758960.1bHLH family protein
XP_009758961.1bHLH family protein
XP_009758962.1bHLH family protein
XP_009760156.1bHLH family protein
XP_009760157.1bHLH family protein
XP_009760399.1bHLH family protein
XP_009760419.1bHLH family protein
XP_009760780.1bHLH family protein
XP_009760781.1bHLH family protein
XP_009761017.1bHLH family protein
XP_009761018.1bHLH family protein
XP_009762311.1bHLH family protein
XP_009762879.1bHLH family protein
XP_009762993.1bHLH family protein
XP_009763212.1bHLH family protein
XP_009763855.1bHLH family protein
XP_009764035.1bHLH family protein
XP_009764528.1bHLH family protein
XP_009764529.1bHLH family protein
XP_009764530.1bHLH family protein
XP_009764628.1bHLH family protein
XP_009765330.1bHLH family protein
XP_009765536.1bHLH family protein
XP_009766851.1bHLH family protein
XP_009766909.1bHLH family protein
XP_009766910.1bHLH family protein
XP_009767140.1bHLH family protein
XP_009767242.1bHLH family protein
XP_009767243.1bHLH family protein
XP_009767537.1bHLH family protein
XP_009767584.1bHLH family protein
XP_009767697.1bHLH family protein
XP_009768125.1bHLH family protein
XP_009768126.1bHLH family protein
XP_009768127.1bHLH family protein
XP_009768432.1bHLH family protein
XP_009768662.1bHLH family protein
XP_009769292.1bHLH family protein
XP_009769541.1bHLH family protein
XP_009769857.1bHLH family protein
XP_009769864.1bHLH family protein
XP_009769873.1bHLH family protein
XP_009770264.1bHLH family protein
XP_009770548.1bHLH family protein
XP_009770549.1bHLH family protein
XP_009771084.1bHLH family protein
XP_009771453.1bHLH family protein
XP_009771454.1bHLH family protein
XP_009771544.1bHLH family protein
XP_009771545.1bHLH family protein
XP_009771547.1bHLH family protein
XP_009771680.1bHLH family protein
XP_009771681.1bHLH family protein
XP_009771720.1bHLH family protein
XP_009772342.1bHLH family protein
XP_009772499.1bHLH family protein
XP_009772518.1bHLH family protein
XP_009773083.1bHLH family protein
XP_009773084.1bHLH family protein
XP_009773320.1bHLH family protein
XP_009773859.1bHLH family protein
XP_009774018.1bHLH family protein
XP_009774164.1bHLH family protein
XP_009774165.1bHLH family protein
XP_009774483.1bHLH family protein
XP_009774484.1bHLH family protein
XP_009774485.1bHLH family protein
XP_009774580.1bHLH family protein
XP_009774581.1bHLH family protein
XP_009774962.1bHLH family protein
XP_009774963.1bHLH family protein
XP_009774964.1bHLH family protein
XP_009775135.1bHLH family protein
XP_009775141.1bHLH family protein
XP_009775258.1bHLH family protein
XP_009775277.1bHLH family protein
XP_009776012.1bHLH family protein
XP_009776013.1bHLH family protein
XP_009776014.1bHLH family protein
XP_009776015.1bHLH family protein
XP_009776117.1bHLH family protein
XP_009776786.1bHLH family protein
XP_009776898.1bHLH family protein
XP_009777020.1bHLH family protein
XP_009777244.1bHLH family protein
XP_009777337.1bHLH family protein
XP_009777338.1bHLH family protein
XP_009777339.1bHLH family protein
XP_009777466.1bHLH family protein
XP_009777959.1bHLH family protein
XP_009778313.1bHLH family protein
XP_009778689.1bHLH family protein
XP_009778719.1bHLH family protein
XP_009778795.1bHLH family protein
XP_009779032.1bHLH family protein
XP_009779237.1bHLH family protein
XP_009779323.1bHLH family protein
XP_009779545.1bHLH family protein
XP_009779730.1bHLH family protein
XP_009779731.1bHLH family protein
XP_009779732.1bHLH family protein
XP_009780303.1bHLH family protein
XP_009780308.1bHLH family protein
XP_009780487.1bHLH family protein
XP_009780893.1bHLH family protein
XP_009781532.1bHLH family protein
XP_009781858.1bHLH family protein
XP_009783164.1bHLH family protein
XP_009783821.1bHLH family protein
XP_009783822.1bHLH family protein
XP_009783823.1bHLH family protein
XP_009784039.1bHLH family protein
XP_009784040.1bHLH family protein
XP_009784041.1bHLH family protein
XP_009784356.1bHLH family protein
XP_009784938.1bHLH family protein
XP_009784940.1bHLH family protein
XP_009784947.1bHLH family protein
XP_009785047.1bHLH family protein
XP_009785053.1bHLH family protein
XP_009785469.1bHLH family protein
XP_009785470.1bHLH family protein
XP_009786139.1bHLH family protein
XP_009786140.1bHLH family protein
XP_009786141.1bHLH family protein
XP_009786142.1bHLH family protein
XP_009786357.1bHLH family protein
XP_009786910.1bHLH family protein
XP_009787611.1bHLH family protein
XP_009787651.1bHLH family protein
XP_009788006.1bHLH family protein
XP_009788007.1bHLH family protein
XP_009788103.1bHLH family protein
XP_009788149.1bHLH family protein
XP_009788151.1bHLH family protein
XP_009788675.1bHLH family protein
XP_009788870.1bHLH family protein
XP_009788923.1bHLH family protein
XP_009790289.1bHLH family protein
XP_009790451.1bHLH family protein
XP_009790621.1bHLH family protein
XP_009790800.1bHLH family protein
XP_009790944.1bHLH family protein
XP_009791053.1bHLH family protein
XP_009791575.1bHLH family protein
XP_009791858.1bHLH family protein
XP_009792481.1bHLH family protein
XP_009792482.1bHLH family protein
XP_009792483.1bHLH family protein
XP_009792484.1bHLH family protein
XP_009792659.1bHLH family protein
XP_009792759.1bHLH family protein
XP_009792846.1bHLH family protein
XP_009792953.1bHLH family protein
XP_009792959.1bHLH family protein
XP_009793126.1bHLH family protein
XP_009793127.1bHLH family protein
XP_009793167.1bHLH family protein
XP_009793272.1bHLH family protein
XP_009793273.1bHLH family protein
XP_009793274.1bHLH family protein
XP_009793632.1bHLH family protein
XP_009793633.1bHLH family protein
XP_009794217.1bHLH family protein
XP_009794455.1bHLH family protein
XP_009794497.1bHLH family protein
XP_009794821.1bHLH family protein
XP_009794822.1bHLH family protein
XP_009795099.1bHLH family protein
XP_009795118.1bHLH family protein
XP_009795428.1bHLH family protein
XP_009795495.1bHLH family protein
XP_009795997.1bHLH family protein
XP_009795998.1bHLH family protein
XP_009796053.1bHLH family protein
XP_009796282.1bHLH family protein
XP_009796478.1bHLH family protein
XP_009796654.1bHLH family protein
XP_009796881.1bHLH family protein
XP_009797668.1bHLH family protein
XP_009797950.1bHLH family protein
XP_009797952.1bHLH family protein
XP_009797953.1bHLH family protein
XP_009797954.1bHLH family protein
XP_009798054.1bHLH family protein
XP_009798055.1bHLH family protein
XP_009798816.1bHLH family protein
XP_009798858.1bHLH family protein
XP_009799029.1bHLH family protein
XP_009800017.1bHLH family protein
XP_009800020.1bHLH family protein
XP_009800420.1bHLH family protein
XP_009800782.1bHLH family protein
XP_009801280.1bHLH family protein
XP_009801370.1bHLH family protein
XP_009801371.1bHLH family protein
XP_009801441.1bHLH family protein
XP_009801442.1bHLH family protein
XP_009801444.1bHLH family protein
XP_009801585.1bHLH family protein
XP_009801820.1bHLH family protein
XP_009801821.1bHLH family protein
XP_009801822.1bHLH family protein
XP_009801833.1bHLH family protein
XP_009801965.1bHLH family protein
XP_009802434.1bHLH family protein
XP_009802629.1bHLH family protein
XP_009803066.1bHLH family protein
XP_009803067.1bHLH family protein
XP_009803168.1bHLH family protein
XP_009803283.1bHLH family protein
XP_009803326.1bHLH family protein
XP_009803327.1bHLH family protein
XP_009803615.1bHLH family protein
XP_009803678.1bHLH family protein
XP_009803686.1bHLH family protein
XP_009803687.1bHLH family protein
XP_009803795.1bHLH family protein
XP_009803796.1bHLH family protein
XP_009803955.1bHLH family protein
XP_009804256.1bHLH family protein
XP_009804982.1bHLH family protein
XP_009804989.1bHLH family protein
XP_009805005.1bHLH 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