PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Utricularia gibba
bHLH Family
Species TF ID Description
678290589bHLH family protein
678294819bHLH family protein
678295939bHLH family protein
678299023bHLH family protein
678299392bHLH family protein
678300280bHLH family protein
678302563bHLH family protein
678302973bHLH family protein
678306424bHLH family protein
678306774bHLH family protein
678309612bHLH family protein
678310705bHLH family protein
678311340bHLH family protein
678316388bHLH family protein
678317256bHLH family protein
678317588bHLH family protein
678320780bHLH family protein
678321642bHLH family protein
678322207bHLH family protein
678323495bHLH family protein
678323674bHLH family protein
678324956bHLH family protein
678325059bHLH family protein
678329945bHLH family protein
678334805bHLH family protein
678335418bHLH family protein
678336358bHLH family protein
678336376bHLH family protein
678337347bHLH family protein
678338308bHLH family protein
678338545bHLH family protein
678339211bHLH family protein
678341994bHLH family protein
678342352bHLH family protein
678346093bHLH family protein
678346517bHLH family protein
678349170bHLH family protein
678349697bHLH family protein
678351197bHLH family protein
678352598bHLH family protein
678352693bHLH family protein
678357086bHLH family protein
678358124bHLH family protein
678359338bHLH family protein
678364660bHLH family protein
678364731bHLH family protein
678364764bHLH family protein
678367152bHLH family protein
678371183bHLH family protein
678374000bHLH family protein
678375546bHLH family protein
678378148bHLH family protein
678379461bHLH family protein
678380540bHLH family protein
678381455bHLH family protein
678382871bHLH family protein
678383593bHLH family protein
678384977bHLH family protein
678385575bHLH family protein
678385837bHLH family protein
678386220bHLH family protein
678390067bHLH family protein
678390964bHLH family protein
678393046bHLH family protein
678393462bHLH family protein
678396642bHLH family protein
678397134bHLH family protein
678400707bHLH family protein
678401286bHLH family protein
678401646bHLH family protein
678402329bHLH family protein
678407487bHLH family protein
678409370bHLH family protein
678416684bHLH family protein
678426187bHLH family protein
678426975bHLH family protein
678430275bHLH family protein
678431222bHLH family protein
678431714bHLH family protein
678432516bHLH family protein
678433956bHLH family protein
678434169bHLH family protein
678436278bHLH family protein
678436728bHLH family protein
678438959bHLH family protein
678439238bHLH family protein
678439592bHLH family protein
678439652bHLH family protein
678440103bHLH family protein
678441522bHLH family protein
678443273bHLH family protein
678444151bHLH family protein
678444233bHLH family protein
678444286bHLH family protein
678444337bHLH family protein
678444340bHLH family protein
678444380bHLH family protein
678444683bHLH family protein
678444896bHLH family protein
678445275bHLH family protein
678445793bHLH family protein
678447630bHLH family protein
678447645bHLH family protein
678448015bHLH family protein
678448021bHLH family protein
678448455bHLH family protein
678448770bHLH family protein
678449025bHLH family protein
678449202bHLH family protein
678449614bHLH family protein
678449638bHLH family protein
678450982bHLH family protein
678451405bHLH family protein
678451506bHLH family protein
678451685bHLH family protein
678452391bHLH family protein
678452424bHLH family protein
678452635bHLH family protein
678453147bHLH family protein
678453354bHLH family protein
678453979bHLH family protein
678457517bHLH family protein
678458454bHLH family protein
678459075bHLH family protein
678459617bHLH family protein
678459845bHLH family protein
678460752bHLH family protein
678461252bHLH family protein
678463812bHLH family protein
678465621bHLH family protein
678465957bHLH family protein
678466371bHLH 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