PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Citrus clementina
bHLH Family
Species TF ID Description
Ciclev10001249mbHLH family protein
Ciclev10001291mbHLH family protein
Ciclev10001683mbHLH family protein
Ciclev10001768mbHLH family protein
Ciclev10001811mbHLH family protein
Ciclev10001998mbHLH family protein
Ciclev10002083mbHLH family protein
Ciclev10002205mbHLH family protein
Ciclev10002224mbHLH family protein
Ciclev10002250mbHLH family protein
Ciclev10002396mbHLH family protein
Ciclev10003450mbHLH family protein
Ciclev10003738mbHLH family protein
Ciclev10003815mbHLH family protein
Ciclev10003973mbHLH family protein
Ciclev10004862mbHLH family protein
Ciclev10005031mbHLH family protein
Ciclev10005087mbHLH family protein
Ciclev10005233mbHLH family protein
Ciclev10005410mbHLH family protein
Ciclev10005777mbHLH family protein
Ciclev10005872mbHLH family protein
Ciclev10005930mbHLH family protein
Ciclev10005947mbHLH family protein
Ciclev10006413mbHLH family protein
Ciclev10006463mbHLH family protein
Ciclev10006628mbHLH family protein
Ciclev10006639mbHLH family protein
Ciclev10006887mbHLH family protein
Ciclev10006940mbHLH family protein
Ciclev10007150mbHLH family protein
Ciclev10007937mbHLH family protein
Ciclev10008008mbHLH family protein
Ciclev10008192mbHLH family protein
Ciclev10008228mbHLH family protein
Ciclev10008684mbHLH family protein
Ciclev10008724mbHLH family protein
Ciclev10008804mbHLH family protein
Ciclev10008887mbHLH family protein
Ciclev10009285mbHLH family protein
Ciclev10009297mbHLH family protein
Ciclev10009354mbHLH family protein
Ciclev10011214mbHLH family protein
Ciclev10012135mbHLH family protein
Ciclev10012176mbHLH family protein
Ciclev10012453mbHLH family protein
Ciclev10012626mbHLH family protein
Ciclev10012681mbHLH family protein
Ciclev10012974mbHLH family protein
Ciclev10013209mbHLH family protein
Ciclev10013420mbHLH family protein
Ciclev10013640mbHLH family protein
Ciclev10015039mbHLH family protein
Ciclev10015052mbHLH family protein
Ciclev10015054mbHLH family protein
Ciclev10015172mbHLH family protein
Ciclev10015436mbHLH family protein
Ciclev10015437mbHLH family protein
Ciclev10016261mbHLH family protein
Ciclev10016289mbHLH family protein
Ciclev10016381mbHLH family protein
Ciclev10016461mbHLH family protein
Ciclev10016466mbHLH family protein
Ciclev10016501mbHLH family protein
Ciclev10016508mbHLH family protein
Ciclev10016511mbHLH family protein
Ciclev10016787mbHLH family protein
Ciclev10016846mbHLH family protein
Ciclev10016849mbHLH family protein
Ciclev10016850mbHLH family protein
Ciclev10016893mbHLH family protein
Ciclev10016938mbHLH family protein
Ciclev10017474mbHLH family protein
Ciclev10017579mbHLH family protein
Ciclev10017617mbHLH family protein
Ciclev10017674mbHLH family protein
Ciclev10018120mbHLH family protein
Ciclev10018141mbHLH family protein
Ciclev10018993mbHLH family protein
Ciclev10019059mbHLH family protein
Ciclev10019118mbHLH family protein
Ciclev10019123mbHLH family protein
Ciclev10019127mbHLH family protein
Ciclev10019135mbHLH family protein
Ciclev10019219mbHLH family protein
Ciclev10019338mbHLH family protein
Ciclev10019339mbHLH family protein
Ciclev10019397mbHLH family protein
Ciclev10019401mbHLH family protein
Ciclev10019582mbHLH family protein
Ciclev10019585mbHLH family protein
Ciclev10019669mbHLH family protein
Ciclev10019730mbHLH family protein
Ciclev10019749mbHLH family protein
Ciclev10019786mbHLH family protein
Ciclev10019816mbHLH family protein
Ciclev10020053mbHLH family protein
Ciclev10020248mbHLH family protein
Ciclev10020323mbHLH family protein
Ciclev10020360mbHLH family protein
Ciclev10020472mbHLH family protein
Ciclev10020681mbHLH family protein
Ciclev10021443mbHLH family protein
Ciclev10021483mbHLH family protein
Ciclev10021606mbHLH family protein
Ciclev10021971mbHLH family protein
Ciclev10022480mbHLH family protein
Ciclev10022739mbHLH family protein
Ciclev10022741mbHLH family protein
Ciclev10022747mbHLH family protein
Ciclev10023072mbHLH family protein
Ciclev10023770mbHLH family protein
Ciclev10024155mbHLH family protein
Ciclev10024201mbHLH family protein
Ciclev10024422mbHLH family protein
Ciclev10024517mbHLH family protein
Ciclev10025735mbHLH family protein
Ciclev10025967mbHLH family protein
Ciclev10026009mbHLH family protein
Ciclev10026131mbHLH family protein
Ciclev10026220mbHLH family protein
Ciclev10026967mbHLH family protein
Ciclev10026976mbHLH family protein
Ciclev10027092mbHLH family protein
Ciclev10027158mbHLH family protein
Ciclev10027504mbHLH family protein
Ciclev10027889mbHLH family protein
Ciclev10027890mbHLH family protein
Ciclev10028494mbHLH family protein
Ciclev10028782mbHLH family protein
Ciclev10028783mbHLH family protein
Ciclev10028925mbHLH family protein
Ciclev10029784mbHLH family protein
Ciclev10029810mbHLH family protein
Ciclev10030052mbHLH family protein
Ciclev10030105mbHLH family protein
Ciclev10030106mbHLH family protein
Ciclev10030309mbHLH family protein
Ciclev10031028mbHLH family protein
Ciclev10031054mbHLH family protein
Ciclev10031066mbHLH family protein
Ciclev10031122mbHLH family protein
Ciclev10031135mbHLH family protein
Ciclev10031143mbHLH family protein
Ciclev10031164mbHLH family protein
Ciclev10031398mbHLH family protein
Ciclev10031621mbHLH family protein
Ciclev10031622mbHLH family protein
Ciclev10031873mbHLH family protein
Ciclev10031900mbHLH family protein
Ciclev10032020mbHLH family protein
Ciclev10032060mbHLH family protein
Ciclev10032062mbHLH family protein
Ciclev10032101mbHLH family protein
Ciclev10032133mbHLH family protein
Ciclev10032241mbHLH family protein
Ciclev10032307mbHLH family protein
Ciclev10032356mbHLH family protein
Ciclev10032412mbHLH family protein
Ciclev10033182mbHLH family protein
Ciclev10033398mbHLH family protein
Ciclev10033428mbHLH family protein
Ciclev10033497mbHLH 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