PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Arabidopsis thaliana
bHLH Family
Species TF ID Description
AT1G01260.1bHLH family protein
AT1G01260.2bHLH family protein
AT1G01260.3bHLH family protein
AT1G02340.1bHLH family protein
AT1G03040.1bHLH family protein
AT1G03040.2bHLH family protein
AT1G05710.1bHLH family protein
AT1G05710.2bHLH family protein
AT1G05710.3bHLH family protein
AT1G05710.4bHLH family protein
AT1G05710.5bHLH family protein
AT1G05805.1bHLH family protein
AT1G06170.1bHLH family protein
AT1G06170.2bHLH family protein
AT1G09530.1phytochrome interacting factor 3
AT1G09530.2phytochrome interacting factor 3
AT1G10120.1bHLH family protein
AT1G10585.1bHLH family protein
AT1G10586.1bHLH family protein
AT1G10610.1bHLH family protein
AT1G12540.1bHLH family protein
AT1G12860.1bHLH family protein
AT1G15790.1
AT1G15790.2
AT1G18400.1BR enhanced expression 1
AT1G22490.1bHLH family protein
AT1G25310.1bHLH family protein
AT1G25330.1bHLH family protein
AT1G26260.1cryptochrome-interacting basic-helix-loop-helix 5
AT1G26260.2cryptochrome-interacting basic-helix-loop-helix 5
AT1G26260.3cryptochrome-interacting basic-helix-loop-helix 5
AT1G26945.1bHLH family protein
AT1G27660.1bHLH family protein
AT1G27740.1root hair defective 6-like 4
AT1G29950.1bHLH family protein
AT1G29950.2bHLH family protein
AT1G30670.1bHLH family protein
AT1G31050.1bHLH family protein
AT1G32640.1bHLH family protein
AT1G35460.1bHLH family protein
AT1G49770.1bHLH family protein
AT1G51070.1bHLH family protein
AT1G51070.2bHLH family protein
AT1G51140.1bHLH family protein
AT1G59640.1BIG PETAL P
AT1G59640.2BIG PETAL P
AT1G61660.1bHLH family protein
AT1G61660.2bHLH family protein
AT1G61660.3bHLH family protein
AT1G61660.4bHLH family protein
AT1G62975.1bHLH family protein
AT1G63650.1bHLH family protein
AT1G63650.2bHLH family protein
AT1G63650.3bHLH family protein
AT1G66470.1ROOT HAIR DEFECTIVE6
AT1G68240.1bHLH family protein
AT1G68240.2bHLH family protein
AT1G68810.1bHLH family protein
AT1G68920.1bHLH family protein
AT1G68920.2bHLH family protein
AT1G68920.3bHLH family protein
AT1G69010.1BES1-interacting Myc-like protein 2
AT1G71200.1bHLH family protein
AT1G72210.1bHLH family protein
AT1G73830.1BR enhanced expression 3
AT1G73830.2BR enhanced expression 3
AT1G74500.1activation-tagged BRI1(brassinosteroid-insensitive 1)-suppressor 1
AT2G14760.1bHLH family protein
AT2G14760.3bHLH family protein
AT2G16910.1bHLH family protein
AT2G18300.1bHLH family protein
AT2G18300.2bHLH family protein
AT2G18300.3bHLH family protein
AT2G20180.1phytochrome interacting factor 3-like 5
AT2G20180.2phytochrome interacting factor 3-like 5
AT2G20180.3phytochrome interacting factor 3-like 5
AT2G22750.1bHLH family protein
AT2G22750.2bHLH family protein
AT2G22760.1bHLH family protein
AT2G22770.1bHLH family protein
AT2G24260.1LJRHL1-like 1
AT2G28160.1FER-like regulator of iron uptake
AT2G31210.1bHLH family protein
AT2G31215.1bHLH family protein
AT2G31220.1bHLH family protein
AT2G31280.1conserved peptide upstream open reading frame 7
AT2G31280.2conserved peptide upstream open reading frame 7
AT2G31280.3conserved peptide upstream open reading frame 7
AT2G31730.1bHLH family protein
AT2G34820.1bHLH family protein
AT2G40200.1bHLH family protein
AT2G41130.1bHLH family protein
AT2G41240.1basic helix-loop-helix protein 100
AT2G41240.2basic helix-loop-helix protein 100
AT2G42280.1bHLH family protein
AT2G42300.1bHLH family protein
AT2G42300.2bHLH family protein
AT2G43010.1phytochrome interacting factor 4
AT2G43010.2phytochrome interacting factor 4
AT2G43140.1bHLH family protein
AT2G43140.2bHLH family protein
AT2G46510.1ABA-inducible BHLH-type transcription factor
AT2G46810.1bHLH family protein
AT2G46970.1phytochrome interacting factor 3-like 1
AT3G06120.1bHLH family protein
AT3G06590.1bHLH family protein
AT3G06590.2bHLH family protein
AT3G07340.1bHLH family protein
AT3G19500.1bHLH family protein
AT3G19860.1bHLH family protein
AT3G19860.2bHLH family protein
AT3G20640.1bHLH family protein
AT3G21330.1bHLH family protein
AT3G22100.1bHLH family protein
AT3G23210.1bHLH family protein
AT3G23690.1bHLH family protein
AT3G24140.1bHLH family protein
AT3G25710.1basic helix-loop-helix 32
AT3G26744.1bHLH family protein
AT3G26744.2bHLH family protein
AT3G26744.4bHLH family protein
AT3G28857.1bHLH family protein
AT3G47640.1bHLH family protein
AT3G47640.2bHLH family protein
AT3G47640.3bHLH family protein
AT3G47710.1BANQUO 3
AT3G50330.1bHLH family protein
AT3G56770.1bHLH family protein
AT3G56770.2bHLH family protein
AT3G56970.1bHLH family protein
AT3G56980.1bHLH family protein
AT3G57800.1bHLH family protein
AT3G57800.2bHLH family protein
AT3G59060.1phytochrome interacting factor 3-like 6
AT3G59060.2phytochrome interacting factor 3-like 6
AT3G59060.3phytochrome interacting factor 3-like 6
AT3G59060.4phytochrome interacting factor 3-like 6
AT3G61950.1bHLH family protein
AT3G61950.2bHLH family protein
AT3G62090.1phytochrome interacting factor 3-like 2
AT3G62090.2phytochrome interacting factor 3-like 2
AT4G00050.1bHLH family protein
AT4G00120.1bHLH family protein
AT4G00480.1bHLH family protein
AT4G00480.2bHLH family protein
AT4G00870.1bHLH family protein
AT4G01460.1bHLH family protein
AT4G02590.1bHLH family protein
AT4G02590.2bHLH family protein
AT4G02590.3bHLH family protein
AT4G05170.1bHLH family protein
AT4G09180.1bHLH family protein
AT4G09820.1bHLH family protein
AT4G14410.1bHLH family protein
AT4G14410.2bHLH family protein
AT4G16430.1bHLH family protein
AT4G17880.1bHLH family protein
AT4G20970.1bHLH family protein
AT4G21330.1bHLH family protein
AT4G21340.1bHLH family protein
AT4G25400.1bHLH family protein
AT4G25410.1bHLH family protein
AT4G28790.1bHLH family protein
AT4G28790.2bHLH family protein
AT4G28800.1bHLH family protein
AT4G28811.1bHLH family protein
AT4G28815.1bHLH family protein
AT4G29100.1bHLH family protein
AT4G29930.1bHLH family protein
AT4G29930.2bHLH family protein
AT4G29930.3bHLH family protein
AT4G29930.4bHLH family protein
AT4G30980.1LJRHL1-like 2
AT4G33880.1ROOT HAIR DEFECTIVE 6-LIKE 2
AT4G34530.1cryptochrome-interacting basic-helix-loop-helix 1
AT4G36060.1bHLH family protein
AT4G36060.2bHLH family protein
AT4G36540.1BR enhanced expression 2
AT4G36540.2BR enhanced expression 2
AT4G36930.1bHLH family protein
AT4G37850.1bHLH family protein
AT4G38070.1bHLH family protein
AT5G01310.1APRATAXIN-like
AT5G04150.1bHLH family protein
AT5G08130.1bHLH family protein
AT5G08130.2bHLH family protein
AT5G08130.3bHLH family protein
AT5G08130.4bHLH family protein
AT5G08130.5bHLH family protein
AT5G08130.6bHLH family protein
AT5G09750.1bHLH family protein
AT5G10570.1bHLH family protein
AT5G15160.1BANQUO 2
AT5G37800.1RHD SIX-LIKE 1
AT5G38860.1BES1-interacting Myc-like protein 3
AT5G39860.1bHLH family protein
AT5G41315.1bHLH family protein
AT5G43175.1bHLH family protein
AT5G43650.1bHLH family protein
AT5G46690.1beta HLH protein 71
AT5G46760.1bHLH family protein
AT5G46830.1NACL-inducible gene 1
AT5G48560.1bHLH family protein
AT5G50915.1bHLH family protein
AT5G50915.2bHLH family protein
AT5G51780.1bHLH family protein
AT5G51790.1bHLH family protein
AT5G53210.1bHLH family protein
AT5G54680.1bHLH family protein
AT5G56960.1bHLH family protein
AT5G57150.1bHLH family protein
AT5G57150.2bHLH family protein
AT5G57150.3bHLH family protein
AT5G57150.4bHLH family protein
AT5G58010.1LJRHL1-like 3
AT5G61270.1phytochrome-interacting factor7
AT5G61270.2phytochrome-interacting factor7
AT5G62610.1bHLH family protein
AT5G65320.1bHLH family protein
AT5G65640.1beta HLH protein 93
AT5G65640.2beta HLH protein 93
AT5G67060.1bHLH family protein
AT5G67110.1bHLH family protein
AT5G67110.2bHLH family protein
AT5G67110.3bHLH 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