PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Daucus carota
bHLH Family
Species TF ID Description
DCAR_000434bHLH family protein
DCAR_000540bHLH family protein
DCAR_000544bHLH family protein
DCAR_000545bHLH family protein
DCAR_000616bHLH family protein
DCAR_001361bHLH family protein
DCAR_001572bHLH family protein
DCAR_001687bHLH family protein
DCAR_001795bHLH family protein
DCAR_002048bHLH family protein
DCAR_002356bHLH family protein
DCAR_002688bHLH family protein
DCAR_002739bHLH family protein
DCAR_003527bHLH family protein
DCAR_003829bHLH family protein
DCAR_004166bHLH family protein
DCAR_004178bHLH family protein
DCAR_004239bHLH family protein
DCAR_004291bHLH family protein
DCAR_004632bHLH family protein
DCAR_004707bHLH family protein
DCAR_004708bHLH family protein
DCAR_004752bHLH family protein
DCAR_004769bHLH family protein
DCAR_005396bHLH family protein
DCAR_005536bHLH family protein
DCAR_005631bHLH family protein
DCAR_006116bHLH family protein
DCAR_006122bHLH family protein
DCAR_006303bHLH family protein
DCAR_006548bHLH family protein
DCAR_006550bHLH family protein
DCAR_006551bHLH family protein
DCAR_006552bHLH family protein
DCAR_006987bHLH family protein
DCAR_006988bHLH family protein
DCAR_007080bHLH family protein
DCAR_007086bHLH family protein
DCAR_007143bHLH family protein
DCAR_007211bHLH family protein
DCAR_007224bHLH family protein
DCAR_007515bHLH family protein
DCAR_007601bHLH family protein
DCAR_007817bHLH family protein
DCAR_008102bHLH family protein
DCAR_008106bHLH family protein
DCAR_008114bHLH family protein
DCAR_008117bHLH family protein
DCAR_008254bHLH family protein
DCAR_008270bHLH family protein
DCAR_009550bHLH family protein
DCAR_009888bHLH family protein
DCAR_009965bHLH family protein
DCAR_010002bHLH family protein
DCAR_010015bHLH family protein
DCAR_010178bHLH family protein
DCAR_010463bHLH family protein
DCAR_010625bHLH family protein
DCAR_010739bHLH family protein
DCAR_010759bHLH family protein
DCAR_010766bHLH family protein
DCAR_010767bHLH family protein
DCAR_010769bHLH family protein
DCAR_010770bHLH family protein
DCAR_011136bHLH family protein
DCAR_011142bHLH family protein
DCAR_011357bHLH family protein
DCAR_011967bHLH family protein
DCAR_012331bHLH family protein
DCAR_012515bHLH family protein
DCAR_012684bHLH family protein
DCAR_012813bHLH family protein
DCAR_012875bHLH family protein
DCAR_013566bHLH family protein
DCAR_013568bHLH family protein
DCAR_013646bHLH family protein
DCAR_014190bHLH family protein
DCAR_014197bHLH family protein
DCAR_014476bHLH family protein
DCAR_014671bHLH family protein
DCAR_014672bHLH family protein
DCAR_014673bHLH family protein
DCAR_014674bHLH family protein
DCAR_015144bHLH family protein
DCAR_015369bHLH family protein
DCAR_015681bHLH family protein
DCAR_015869bHLH family protein
DCAR_016180bHLH family protein
DCAR_017032bHLH family protein
DCAR_017942bHLH family protein
DCAR_018019bHLH family protein
DCAR_018020bHLH family protein
DCAR_018023bHLH family protein
DCAR_018026bHLH family protein
DCAR_018028bHLH family protein
DCAR_018135bHLH family protein
DCAR_018460bHLH family protein
DCAR_018679bHLH family protein
DCAR_019207bHLH family protein
DCAR_019332bHLH family protein
DCAR_019383bHLH family protein
DCAR_019435bHLH family protein
DCAR_019446bHLH family protein
DCAR_020069bHLH family protein
DCAR_020074bHLH family protein
DCAR_020305bHLH family protein
DCAR_020561bHLH family protein
DCAR_020568bHLH family protein
DCAR_020569bHLH family protein
DCAR_020925bHLH family protein
DCAR_021193bHLH family protein
DCAR_021251bHLH family protein
DCAR_021286bHLH family protein
DCAR_021411bHLH family protein
DCAR_021531bHLH family protein
DCAR_021549bHLH family protein
DCAR_021919bHLH family protein
DCAR_021955bHLH family protein
DCAR_022244bHLH family protein
DCAR_022499bHLH family protein
DCAR_022520bHLH family protein
DCAR_022765bHLH family protein
DCAR_022957bHLH family protein
DCAR_022979bHLH family protein
DCAR_023730bHLH family protein
DCAR_023757bHLH family protein
DCAR_024117bHLH family protein
DCAR_024199bHLH family protein
DCAR_024900bHLH family protein
DCAR_024901bHLH family protein
DCAR_024963bHLH family protein
DCAR_025008bHLH family protein
DCAR_025094bHLH family protein
DCAR_025258bHLH family protein
DCAR_025656bHLH family protein
DCAR_025738bHLH family protein
DCAR_025840bHLH family protein
DCAR_025842bHLH family protein
DCAR_025855bHLH family protein
DCAR_026020bHLH family protein
DCAR_026040bHLH family protein
DCAR_026065bHLH family protein
DCAR_026090bHLH family protein
DCAR_026126bHLH family protein
DCAR_026259bHLH family protein
DCAR_026367bHLH family protein
DCAR_026538bHLH family protein
DCAR_026607bHLH family protein
DCAR_026671bHLH family protein
DCAR_026689bHLH family protein
DCAR_026740bHLH family protein
DCAR_027105bHLH family protein
DCAR_027267bHLH family protein
DCAR_027275bHLH family protein
DCAR_027276bHLH family protein
DCAR_027401bHLH family protein
DCAR_028008bHLH family protein
DCAR_028691bHLH family protein
DCAR_029122bHLH family protein
DCAR_029297bHLH family protein
DCAR_029561bHLH family protein
DCAR_029642bHLH family protein
DCAR_030086bHLH family protein
DCAR_030559bHLH family protein
DCAR_030600bHLH family protein
DCAR_031033bHLH family protein
DCAR_031077bHLH family protein
DCAR_031333bHLH family protein
DCAR_031419bHLH family protein
DCAR_031998bHLH family protein
DCAR_032206bHLH 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