PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Capsella rubella
bHLH Family
Species TF ID Description
Carubv10000576mbHLH family protein
Carubv10000655mbHLH family protein
Carubv10001082mbHLH family protein
Carubv10001470mbHLH family protein
Carubv10001486mbHLH family protein
Carubv10001523mbHLH family protein
Carubv10001567mbHLH family protein
Carubv10001721mbHLH family protein
Carubv10001734mbHLH family protein
Carubv10002337mbHLH family protein
Carubv10002462mbHLH family protein
Carubv10003163mbHLH family protein
Carubv10003683mbHLH family protein
Carubv10003900mbHLH family protein
Carubv10003996mbHLH family protein
Carubv10004345mbHLH family protein
Carubv10004392mbHLH family protein
Carubv10004930mbHLH family protein
Carubv10005062mbHLH family protein
Carubv10005083mbHLH family protein
Carubv10005248mbHLH family protein
Carubv10005334mbHLH family protein
Carubv10005335mbHLH family protein
Carubv10005784mbHLH family protein
Carubv10006122mbHLH family protein
Carubv10006264mbHLH family protein
Carubv10006422mbHLH family protein
Carubv10006445mbHLH family protein
Carubv10006623mbHLH family protein
Carubv10006739mbHLH family protein
Carubv10006834mbHLH family protein
Carubv10006934mbHLH family protein
Carubv10006994mbHLH family protein
Carubv10007002mbHLH family protein
Carubv10007380mbHLH family protein
Carubv10007389mbHLH family protein
Carubv10007459mbHLH family protein
Carubv10007725mbHLH family protein
Carubv10008586mbHLH family protein
Carubv10008640mbHLH family protein
Carubv10008815mbHLH family protein
Carubv10009081mbHLH family protein
Carubv10009095mbHLH family protein
Carubv10009102mbHLH family protein
Carubv10009158mbHLH family protein
Carubv10009161mbHLH family protein
Carubv10009189mbHLH family protein
Carubv10009210mbHLH family protein
Carubv10009240mbHLH family protein
Carubv10009382mbHLH family protein
Carubv10009458mbHLH family protein
Carubv10009514mbHLH family protein
Carubv10009652mbHLH family protein
Carubv10009831mbHLH family protein
Carubv10009894mbHLH family protein
Carubv10010050mbHLH family protein
Carubv10010416mbHLH family protein
Carubv10010563mbHLH family protein
Carubv10010568mbHLH family protein
Carubv10010705mbHLH family protein
Carubv10010751mbHLH family protein
Carubv10010961mbHLH family protein
Carubv10011063mbHLH family protein
Carubv10011072mbHLH family protein
Carubv10011373mbHLH family protein
Carubv10011385mbHLH family protein
Carubv10011476mbHLH family protein
Carubv10011628mbHLH family protein
Carubv10011792mbHLH family protein
Carubv10011964mbHLH family protein
Carubv10012043mbHLH family protein
Carubv10012077mbHLH family protein
Carubv10012182mbHLH family protein
Carubv10012751mbHLH family protein
Carubv10013621mbHLH family protein
Carubv10013632mbHLH family protein
Carubv10013649mbHLH family protein
Carubv10013821mbHLH family protein
Carubv10013858mbHLH family protein
Carubv10013859mbHLH family protein
Carubv10013979mbHLH family protein
Carubv10013980mbHLH family protein
Carubv10013989mbHLH family protein
Carubv10014138mbHLH family protein
Carubv10014200mbHLH family protein
Carubv10014310mbHLH family protein
Carubv10014323mbHLH family protein
Carubv10014574mbHLH family protein
Carubv10015484mbHLH family protein
Carubv10016096mbHLH family protein
Carubv10016240mbHLH family protein
Carubv10017096mbHLH family protein
Carubv10017099mbHLH family protein
Carubv10017267mbHLH family protein
Carubv10017353mbHLH family protein
Carubv10017470mbHLH family protein
Carubv10017770mbHLH family protein
Carubv10017822mbHLH family protein
Carubv10017931mbHLH family protein
Carubv10017932mbHLH family protein
Carubv10017947mbHLH family protein
Carubv10018314mbHLH family protein
Carubv10018503mbHLH family protein
Carubv10018554mbHLH family protein
Carubv10018614mbHLH family protein
Carubv10019056mbHLH family protein
Carubv10019130mbHLH family protein
Carubv10019148mbHLH family protein
Carubv10019965mbHLH family protein
Carubv10020178mbHLH family protein
Carubv10020221mbHLH family protein
Carubv10020420mbHLH family protein
Carubv10020515mbHLH family protein
Carubv10020657mbHLH family protein
Carubv10020679mbHLH family protein
Carubv10020802mbHLH family protein
Carubv10020803mbHLH family protein
Carubv10020804mbHLH family protein
Carubv10021322mbHLH family protein
Carubv10021349mbHLH family protein
Carubv10021430mbHLH family protein
Carubv10021596mbHLH family protein
Carubv10021619mbHLH family protein
Carubv10022732mbHLH family protein
Carubv10023056mbHLH family protein
Carubv10023260mbHLH family protein
Carubv10023275mbHLH family protein
Carubv10023299mbHLH family protein
Carubv10023324mbHLH family protein
Carubv10023498mbHLH family protein
Carubv10023506mbHLH family protein
Carubv10023532mbHLH family protein
Carubv10023610mbHLH family protein
Carubv10023618mbHLH family protein
Carubv10023654mbHLH family protein
Carubv10023683mbHLH family protein
Carubv10023707mbHLH family protein
Carubv10023734mbHLH family protein
Carubv10023903mbHLH family protein
Carubv10023940mbHLH family protein
Carubv10024245mbHLH family protein
Carubv10024768mbHLH family protein
Carubv10025041mbHLH family protein
Carubv10025360mbHLH family protein
Carubv10026241mbHLH family protein
Carubv10026331mbHLH family protein
Carubv10026606mbHLH family protein
Carubv10026630mbHLH family protein
Carubv10026748mbHLH family protein
Carubv10026758mbHLH family protein
Carubv10026852mbHLH family protein
Carubv10026916mbHLH family protein
Carubv10027158mbHLH family protein
Carubv10027166mbHLH family protein
Carubv10027660mbHLH family protein
Carubv10027730mbHLH family protein
Carubv10027898mbHLH family protein
Carubv10027920mbHLH family protein
Carubv10028430mbHLH family protein
Carubv10028441mbHLH family protein
Carubv10028492mbHLH family protein
Carubv10028570mbHLH family protein
Carubv10028625mbHLH 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