PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Picea abies
bHLH Family
Species TF ID Description
MA_10156436g0010bHLH family protein
MA_10157g0010bHLH family protein
MA_10426320g0010bHLH family protein
MA_10427394g0020bHLH family protein
MA_10431176g0010bHLH family protein
MA_10431722g0010bHLH family protein
MA_10431811g0010bHLH family protein
MA_10432060g0010bHLH family protein
MA_10432919g0010bHLH family protein
MA_10433418g0010bHLH family protein
MA_10433428g0010bHLH family protein
MA_10435231g0010bHLH family protein
MA_10435365g0020bHLH family protein
MA_10435905g0020bHLH family protein
MA_10436183g0010bHLH family protein
MA_110122g0010bHLH family protein
MA_114573g0010bHLH family protein
MA_120602g0010bHLH family protein
MA_121950g0010bHLH family protein
MA_1220g0010bHLH family protein
MA_126261g0010bHLH family protein
MA_126263g0010bHLH family protein
MA_130776g0010bHLH family protein
MA_132680g0010bHLH family protein
MA_13676g0010bHLH family protein
MA_141469g0010bHLH family protein
MA_14544g0010bHLH family protein
MA_148495g0010bHLH family protein
MA_148785g0010bHLH family protein
MA_155093g0010bHLH family protein
MA_156285g0010bHLH family protein
MA_158362g0010bHLH family protein
MA_158850g0010bHLH family protein
MA_15962g0010bHLH family protein
MA_16454g0010bHLH family protein
MA_16489g0010bHLH family protein
MA_17689g0010bHLH family protein
MA_178280g0020bHLH family protein
MA_178860g0010bHLH family protein
MA_18042g0010bHLH family protein
MA_18777g0020bHLH family protein
MA_18800g0020bHLH family protein
MA_196213g0010bHLH family protein
MA_196775g0010bHLH family protein
MA_20452g0010bHLH family protein
MA_20585g0010bHLH family protein
MA_213558g0010bHLH family protein
MA_214240g0010bHLH family protein
MA_221221g0010bHLH family protein
MA_239753g0010bHLH family protein
MA_257886g0010bHLH family protein
MA_26114g0010bHLH family protein
MA_283702g0010bHLH family protein
MA_28638g0010bHLH family protein
MA_28961g0020bHLH family protein
MA_290659g0010bHLH family protein
MA_29186g0010bHLH family protein
MA_293538g0010bHLH family protein
MA_306658g0010bHLH family protein
MA_317126g0010bHLH family protein
MA_321195g0010bHLH family protein
MA_363763g0010bHLH family protein
MA_3940g0010bHLH family protein
MA_4076g0010bHLH family protein
MA_42080g0010bHLH family protein
MA_4395g0010bHLH family protein
MA_439607g0010bHLH family protein
MA_448849g0010bHLH family protein
MA_45470g0010bHLH family protein
MA_46112g0010bHLH family protein
MA_465203g0020bHLH family protein
MA_476980g0010bHLH family protein
MA_479454g0010bHLH family protein
MA_504223g0010bHLH family protein
MA_50630g0010bHLH family protein
MA_52085g0010bHLH family protein
MA_570300g0010bHLH family protein
MA_57244g0010bHLH family protein
MA_57676g0010bHLH family protein
MA_57970g0010bHLH family protein
MA_5838g0020bHLH family protein
MA_616354g0010bHLH family protein
MA_63506g0010bHLH family protein
MA_65818g0010bHLH family protein
MA_66378g0010bHLH family protein
MA_66681g0010bHLH family protein
MA_686524g0010bHLH family protein
MA_690904g0010bHLH family protein
MA_69506g0010bHLH family protein
MA_733169g0010bHLH family protein
MA_7437390g0010bHLH family protein
MA_76955g0010bHLH family protein
MA_7848375g0010bHLH family protein
MA_8183g0010bHLH family protein
MA_8255g0010bHLH family protein
MA_82688g0010bHLH family protein
MA_88831g0010bHLH family protein
MA_90272g0010bHLH family protein
MA_9115341g0010bHLH family protein
MA_9119217g0010bHLH family protein
MA_917739g0010bHLH family protein
MA_9207013g0020bHLH family protein
MA_92168g0010bHLH family protein
MA_93736g0010bHLH family protein
MA_96585g0010bHLH family protein
MA_96671g0010bHLH family protein
MA_97786g0010bHLH 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