PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Nelumbo nucifera
bHLH Family
Species TF ID Description
NNU_000503-RAbHLH family protein
NNU_000704-RAbHLH family protein
NNU_000778-RAbHLH family protein
NNU_000788-RAbHLH family protein
NNU_000800-RAbHLH family protein
NNU_000841-RAbHLH family protein
NNU_001052-RAbHLH family protein
NNU_001071-RAbHLH family protein
NNU_001170-RAbHLH family protein
NNU_001267-RAbHLH family protein
NNU_001366-RAbHLH family protein
NNU_001560-RAbHLH family protein
NNU_001578-RAbHLH family protein
NNU_001699-RAbHLH family protein
NNU_001794-RAbHLH family protein
NNU_002022-RAbHLH family protein
NNU_002061-RAbHLH family protein
NNU_002291-RAbHLH family protein
NNU_002730-RAbHLH family protein
NNU_003204-RAbHLH family protein
NNU_003217-RAbHLH family protein
NNU_003426-RAbHLH family protein
NNU_003427-RAbHLH family protein
NNU_003442-RAbHLH family protein
NNU_003962-RAbHLH family protein
NNU_003979-RAbHLH family protein
NNU_004386-RAbHLH family protein
NNU_004410-RAbHLH family protein
NNU_004947-RAbHLH family protein
NNU_005785-RAbHLH family protein
NNU_005911-RAbHLH family protein
NNU_006193-RAbHLH family protein
NNU_006282-RAbHLH family protein
NNU_006343-RAbHLH family protein
NNU_006380-RAbHLH family protein
NNU_006703-RAbHLH family protein
NNU_007035-RAbHLH family protein
NNU_007057-RAbHLH family protein
NNU_007471-RAbHLH family protein
NNU_007473-RAbHLH family protein
NNU_007583-RAbHLH family protein
NNU_007801-RAbHLH family protein
NNU_007924-RAbHLH family protein
NNU_008221-RAbHLH family protein
NNU_008242-RAbHLH family protein
NNU_008541-RAbHLH family protein
NNU_008831-RAbHLH family protein
NNU_009308-RAbHLH family protein
NNU_009596-RAbHLH family protein
NNU_009875-RAbHLH family protein
NNU_010278-RAbHLH family protein
NNU_010414-RAbHLH family protein
NNU_010531-RAbHLH family protein
NNU_010757-RAbHLH family protein
NNU_010873-RAbHLH family protein
NNU_010934-RAbHLH family protein
NNU_011612-RAbHLH family protein
NNU_011613-RAbHLH family protein
NNU_011636-RAbHLH family protein
NNU_011682-RAbHLH family protein
NNU_011728-RAbHLH family protein
NNU_011947-RAbHLH family protein
NNU_012009-RAbHLH family protein
NNU_012138-RAbHLH family protein
NNU_012308-RAbHLH family protein
NNU_012609-RAbHLH family protein
NNU_012728-RAbHLH family protein
NNU_012886-RAbHLH family protein
NNU_012893-RAbHLH family protein
NNU_013112-RAbHLH family protein
NNU_013503-RAbHLH family protein
NNU_013913-RAbHLH family protein
NNU_014018-RAbHLH family protein
NNU_014025-RAbHLH family protein
NNU_014127-RAbHLH family protein
NNU_014363-RAbHLH family protein
NNU_014413-RAbHLH family protein
NNU_014585-RAbHLH family protein
NNU_015909-RAbHLH family protein
NNU_016243-RAbHLH family protein
NNU_016299-RAbHLH family protein
NNU_016667-RAbHLH family protein
NNU_016825-RAbHLH family protein
NNU_017018-RAbHLH family protein
NNU_017197-RAbHLH family protein
NNU_017467-RAbHLH family protein
NNU_017704-RAbHLH family protein
NNU_017716-RAbHLH family protein
NNU_017998-RAbHLH family protein
NNU_018556-RAbHLH family protein
NNU_018579-RAbHLH family protein
NNU_018728-RAbHLH family protein
NNU_018860-RAbHLH family protein
NNU_019107-RAbHLH family protein
NNU_019274-RAbHLH family protein
NNU_019377-RAbHLH family protein
NNU_019613-RAbHLH family protein
NNU_019998-RAbHLH family protein
NNU_020529-RAbHLH family protein
NNU_020716-RAbHLH family protein
NNU_021004-RAbHLH family protein
NNU_021392-RAbHLH family protein
NNU_021557-RAbHLH family protein
NNU_021882-RAbHLH family protein
NNU_021919-RAbHLH family protein
NNU_022047-RAbHLH family protein
NNU_022087-RAbHLH family protein
NNU_022277-RAbHLH family protein
NNU_022633-RAbHLH family protein
NNU_022880-RAbHLH family protein
NNU_022892-RAbHLH family protein
NNU_022902-RAbHLH family protein
NNU_022998-RAbHLH family protein
NNU_023133-RAbHLH family protein
NNU_023246-RAbHLH family protein
NNU_023481-RAbHLH family protein
NNU_023611-RAbHLH family protein
NNU_023650-RAbHLH family protein
NNU_024298-RAbHLH family protein
NNU_024965-RAbHLH family protein
NNU_025116-RAbHLH family protein
NNU_025179-RAbHLH family protein
NNU_025398-RAbHLH family protein
NNU_025658-RAbHLH family protein
NNU_025685-RAbHLH family protein
NNU_025686-RAbHLH family protein
NNU_026428-RAbHLH 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