An E-box is a DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 sequence which usually lies upstream of a gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

 in a promoter region. It is a transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

 binding site where the specific sequence of DNA, CANNTG, is recognized by proteins that can bind to it to help initiate its transcription

Transcription (genetics)

Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

. Once transcription factors bind to promoters, they allow for association of other enzymes which will copy the DNA into mRNA. The consensus sequence

Consensus sequence

In molecular biology and bioinformatics, consensus sequence refers to the most common nucleotide or amino acid at a particular position after multiple sequences are aligned. A consensus sequence is a way of representing the results of a multiple sequence alignment, where related sequences are...

 for the E-box element is CANNTG, with a palindromic canonical sequence of CACGTG. Transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

s containing the basic-helix-loop-helix

Basic-helix-loop-helix

A basic helix-loop-helix is a protein structural motif that characterizes a family of transcription factors.- Structure :The motif is characterized by two α-helices connected by a loop. In general, transcription factors including this domain are dimeric, each with one helix containing basic amino...

 protein structural motif

Structural motif

In a chain-like biological molecule, such as a protein or nucleic acid, a structural motif is a supersecondary structure, which appears also in a variety of other molecules...

 typically bind to E-boxes or related variant sequences and enhance transcription

Transcription (genetics)

Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

 of the downstream gene.

Proteins that interact with E-boxes

• E47
• Beta2/NeuroD1
• MyoD
  MyoD
  MyoD is a protein with a key role in regulating muscle differentiation. MyoD belongs to a family of proteins known as myogenic regulatory factors . These bHLH transcription factors act sequentially in myogenic differentiation. MRF family members include MyoD, Myf5, myogenin, and MRF4 .MyoD is one...
  
  
• MyoG
• BMAL
  BMAL
  Bmal is a gene that encodes proteins regulating circadian rhythm. BMAL proteins form part of a basic-helix-loop-helix transcription factor. BMAL-1 dimerizes with CLOCK in vivo and transactivates gene expression of Period and Timeless in drosophila by binding to E-box elements in their promoters...
  
  -CLOCK
  CLOCK
  Clock is a gene encoding a basic-helix-loop-helix-PAS transcription factor that affects both the persistence and period of circadian rhythms...
  
  
• c-Myc