PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Catharanthus roseus
bHLH Family
Species TF ID Description
cra_locus_10082_iso_3bHLH family protein
cra_locus_10223_iso_1bHLH family protein
cra_locus_10223_iso_2bHLH family protein
cra_locus_10223_iso_4bHLH family protein
cra_locus_10223_iso_5bHLH family protein
cra_locus_10414_iso_2bHLH family protein
cra_locus_10414_iso_4bHLH family protein
cra_locus_10414_iso_5bHLH family protein
cra_locus_10414_iso_6bHLH family protein
cra_locus_10414_iso_8bHLH family protein
cra_locus_104520_iso_1bHLH family protein
cra_locus_10503_iso_1bHLH family protein
cra_locus_10503_iso_3bHLH family protein
cra_locus_10503_iso_4bHLH family protein
cra_locus_10685_iso_1bHLH family protein
cra_locus_10685_iso_2bHLH family protein
cra_locus_10685_iso_3bHLH family protein
cra_locus_10685_iso_4bHLH family protein
cra_locus_10685_iso_5bHLH family protein
cra_locus_10685_iso_6bHLH family protein
cra_locus_1072_iso_2bHLH family protein
cra_locus_10934_iso_1bHLH family protein
cra_locus_113547_iso_1bHLH family protein
cra_locus_11711_iso_1bHLH family protein
cra_locus_11711_iso_2bHLH family protein
cra_locus_11711_iso_4bHLH family protein
cra_locus_11745_iso_1bHLH family protein
cra_locus_11745_iso_2bHLH family protein
cra_locus_11745_iso_3bHLH family protein
cra_locus_11812_iso_1bHLH family protein
cra_locus_11812_iso_2bHLH family protein
cra_locus_12077_iso_2bHLH family protein
cra_locus_12077_iso_3bHLH family protein
cra_locus_12077_iso_5bHLH family protein
cra_locus_12175_iso_1bHLH family protein
cra_locus_12175_iso_3bHLH family protein
cra_locus_12175_iso_4bHLH family protein
cra_locus_12175_iso_5bHLH family protein
cra_locus_121939_iso_1bHLH family protein
cra_locus_12315_iso_1bHLH family protein
cra_locus_12315_iso_3bHLH family protein
cra_locus_12546_iso_1bHLH family protein
cra_locus_12774_iso_1bHLH family protein
cra_locus_12822_iso_1bHLH family protein
cra_locus_12955_iso_2bHLH family protein
cra_locus_12955_iso_3bHLH family protein
cra_locus_12955_iso_5bHLH family protein
cra_locus_12955_iso_6bHLH family protein
cra_locus_12955_iso_8bHLH family protein
cra_locus_13213_iso_1bHLH family protein
cra_locus_1344_iso_2bHLH family protein
cra_locus_1344_iso_3bHLH family protein
cra_locus_1344_iso_6bHLH family protein
cra_locus_13466_iso_1bHLH family protein
cra_locus_13647_iso_1bHLH family protein
cra_locus_13883_iso_1bHLH family protein
cra_locus_13883_iso_2bHLH family protein
cra_locus_13883_iso_3bHLH family protein
cra_locus_14634_iso_1bHLH family protein
cra_locus_14634_iso_2bHLH family protein
cra_locus_1467_iso_1bHLH family protein
cra_locus_14847_iso_3bHLH family protein
cra_locus_14847_iso_4bHLH family protein
cra_locus_14860_iso_2bHLH family protein
cra_locus_14860_iso_3bHLH family protein
cra_locus_14860_iso_4bHLH family protein
cra_locus_15250_iso_1bHLH family protein
cra_locus_15329_iso_1bHLH family protein
cra_locus_15329_iso_2bHLH family protein
cra_locus_15469_iso_10bHLH family protein
cra_locus_15469_iso_2bHLH family protein
cra_locus_15469_iso_3bHLH family protein
cra_locus_15469_iso_4bHLH family protein
cra_locus_15469_iso_7bHLH family protein
cra_locus_15469_iso_8bHLH family protein
cra_locus_15469_iso_9bHLH family protein
cra_locus_15559_iso_2bHLH family protein
cra_locus_15559_iso_3bHLH family protein
cra_locus_15559_iso_4bHLH family protein
cra_locus_15559_iso_6bHLH family protein
cra_locus_15967_iso_2bHLH family protein
cra_locus_16044_iso_1bHLH family protein
cra_locus_16044_iso_2bHLH family protein
cra_locus_16124_iso_1bHLH family protein
cra_locus_16124_iso_2bHLH family protein
cra_locus_16649_iso_1bHLH family protein
cra_locus_1670_iso_1bHLH family protein
cra_locus_1670_iso_4bHLH family protein
cra_locus_16831_iso_1bHLH family protein
cra_locus_16909_iso_1bHLH family protein
cra_locus_17763_iso_1bHLH family protein
cra_locus_17864_iso_1bHLH family protein
cra_locus_18737_iso_1bHLH family protein
cra_locus_18737_iso_2bHLH family protein
cra_locus_18737_iso_4bHLH family protein
cra_locus_1884_iso_1bHLH family protein
cra_locus_1884_iso_2bHLH family protein
cra_locus_1884_iso_4bHLH family protein
cra_locus_18990_iso_1bHLH family protein
cra_locus_19483_iso_1bHLH family protein
cra_locus_22694_iso_1bHLH family protein
cra_locus_22694_iso_2bHLH family protein
cra_locus_23016_iso_2bHLH family protein
cra_locus_23016_iso_4bHLH family protein
cra_locus_23695_iso_1bHLH family protein
cra_locus_25027_iso_1bHLH family protein
cra_locus_25847_iso_1bHLH family protein
cra_locus_28230_iso_1bHLH family protein
cra_locus_2845_iso_1bHLH family protein
cra_locus_2845_iso_2bHLH family protein
cra_locus_2845_iso_3bHLH family protein
cra_locus_2845_iso_4bHLH family protein
cra_locus_2845_iso_5bHLH family protein
cra_locus_2845_iso_6bHLH family protein
cra_locus_29303_iso_1bHLH family protein
cra_locus_30340_iso_1bHLH family protein
cra_locus_3040_iso_1bHLH family protein
cra_locus_30819_iso_1bHLH family protein
cra_locus_31527_iso_1bHLH family protein
cra_locus_31527_iso_2bHLH family protein
cra_locus_3361_iso_2bHLH family protein
cra_locus_3361_iso_3bHLH family protein
cra_locus_3361_iso_5bHLH family protein
cra_locus_3368_iso_1bHLH family protein
cra_locus_3368_iso_2bHLH family protein
cra_locus_3368_iso_3bHLH family protein
cra_locus_38360_iso_1bHLH family protein
cra_locus_38360_iso_2bHLH family protein
cra_locus_39137_iso_1bHLH family protein
cra_locus_39137_iso_2bHLH family protein
cra_locus_40960_iso_1bHLH family protein
cra_locus_4107_iso_2bHLH family protein
cra_locus_4107_iso_6bHLH family protein
cra_locus_4107_iso_7bHLH family protein
cra_locus_4179_iso_1bHLH family protein
cra_locus_4179_iso_2bHLH family protein
cra_locus_4179_iso_3bHLH family protein
cra_locus_4179_iso_4bHLH family protein
cra_locus_4179_iso_6bHLH family protein
cra_locus_4348_iso_1bHLH family protein
cra_locus_4348_iso_2bHLH family protein
cra_locus_4348_iso_4bHLH family protein
cra_locus_4348_iso_5bHLH family protein
cra_locus_4348_iso_6bHLH family protein
cra_locus_4348_iso_7bHLH family protein
cra_locus_4348_iso_8bHLH family protein
cra_locus_4548_iso_4bHLH family protein
cra_locus_4548_iso_5bHLH family protein
cra_locus_4594_iso_1bHLH family protein
cra_locus_4594_iso_2bHLH family protein
cra_locus_5389_iso_2bHLH family protein
cra_locus_5389_iso_4bHLH family protein
cra_locus_5389_iso_7bHLH family protein
cra_locus_5400_iso_2bHLH family protein
cra_locus_5400_iso_3bHLH family protein
cra_locus_5400_iso_4bHLH family protein
cra_locus_5400_iso_5bHLH family protein
cra_locus_55803_iso_1bHLH family protein
cra_locus_5660_iso_3bHLH family protein
cra_locus_56752_iso_1bHLH family protein
cra_locus_56752_iso_2bHLH family protein
cra_locus_5787_iso_1bHLH family protein
cra_locus_57960_iso_1bHLH family protein
cra_locus_58430_iso_1bHLH family protein
cra_locus_58692_iso_1bHLH family protein
cra_locus_59466_iso_1bHLH family protein
cra_locus_625_iso_3bHLH family protein
cra_locus_625_iso_5bHLH family protein
cra_locus_625_iso_6bHLH family protein
cra_locus_6803_iso_3bHLH family protein
cra_locus_6803_iso_6bHLH family protein
cra_locus_69016_iso_1bHLH family protein
cra_locus_69016_iso_2bHLH family protein
cra_locus_6981_iso_1bHLH family protein
cra_locus_6981_iso_4bHLH family protein
cra_locus_6981_iso_5bHLH family protein
cra_locus_6981_iso_6bHLH family protein
cra_locus_74591_iso_1bHLH family protein
cra_locus_751_iso_1bHLH family protein
cra_locus_751_iso_2bHLH family protein
cra_locus_751_iso_3bHLH family protein
cra_locus_751_iso_4bHLH family protein
cra_locus_7620_iso_1bHLH family protein
cra_locus_7620_iso_2bHLH family protein
cra_locus_7620_iso_3bHLH family protein
cra_locus_7653_iso_1bHLH family protein
cra_locus_7653_iso_2bHLH family protein
cra_locus_7726_iso_1bHLH family protein
cra_locus_7726_iso_5bHLH family protein
cra_locus_7726_iso_6bHLH family protein
cra_locus_7910_iso_1bHLH family protein
cra_locus_7910_iso_2bHLH family protein
cra_locus_7910_iso_8bHLH family protein
cra_locus_7979_iso_2bHLH family protein
cra_locus_7979_iso_3bHLH family protein
cra_locus_8055_iso_1bHLH family protein
cra_locus_8055_iso_3bHLH family protein
cra_locus_8055_iso_4bHLH family protein
cra_locus_8171_iso_2bHLH family protein
cra_locus_8171_iso_4bHLH family protein
cra_locus_8171_iso_5bHLH family protein
cra_locus_8171_iso_6bHLH family protein
cra_locus_8171_iso_8bHLH family protein
cra_locus_8171_iso_9bHLH family protein
cra_locus_83174_iso_1bHLH family protein
cra_locus_8576_iso_1bHLH family protein
cra_locus_8576_iso_2bHLH family protein
cra_locus_9367_iso_1bHLH family protein
cra_locus_9367_iso_3bHLH family protein
cra_locus_9367_iso_4bHLH family protein
cra_locus_9367_iso_5bHLH family protein
cra_locus_9367_iso_6bHLH family protein
cra_locus_941_iso_2bHLH family protein
cra_locus_941_iso_3bHLH family protein
cra_locus_941_iso_5bHLH family protein
cra_locus_9526_iso_1bHLH family protein
cra_locus_9526_iso_2bHLH family protein
cra_locus_9820_iso_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