Related Experiment Video
Updated: Aug 9, 2026

08:18
Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene
Published on: December 31, 2014
Distinct DNA binding preferences for the c-Myc/Max and Max/Max dimers
1Growth Control and Development Laboratory, Imperial Cancer Research Fund, London, UK.
Nucleic Acids Research
|November 25, 1993
Summary
The transcription factor c-Myc/Max binds DNA poorly with certain flanking sequences, unlike Max/Max dimers. This DNA binding difference impacts gene regulation by c-Myc.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- c-Myc and Max form transcription factor dimers crucial for gene regulation.
- These dimers belong to the basic/helix-loop-helix/leucine-zipper (bHLH-Z) family.
- They bind to specific DNA sequences, including the core CACGTG.
Purpose of the Study:
- To determine the complete consensus DNA binding sites for c-Myc/Max and Max/Max dimers.
- To investigate the influence of flanking DNA sequences on dimer binding affinity.
- To assess the in vivo impact of flanking sequences on c-Myc-mediated transactivation.
Main Methods:
- Site-selection protocol to identify DNA binding preferences.
- Analysis of 12 base pair consensus binding sites for c-Myc/Max and Max/Max.
- In vivo experiments to evaluate transactivation by c-Myc.
Main Results:
- The consensus binding site for c-Myc/Max is RACCACGTGGTY.
- The consensus binding site for Max/Max is RANCACGTGNTY.
- c-Myc/Max dimers are inhibited by 5'T or 3'A flanking sequences, while Max/Max dimers bind these sites readily.
- Inappropriate flanking sequences prevent c-Myc transactivation in vivo.
Conclusions:
- Max/Max dimers exhibit broader DNA binding specificity compared to c-Myc/Max dimers.
- Max/Max dimers may regulate a wider range of genes, potentially including those not targeted by c-Myc/Max.
- Flanking sequences play a critical role in determining the regulatory targets of c-Myc/Max transcription factors.
Related Concept Videos
Euchromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...

