Related Experiment Video
Updated: May 12, 2026

Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
An intermolecular disulfide bond stabilizes E2A homodimers and is required for DNA binding at physiological
1Cell Biology and Genetics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
Abstract:
It is demonstrated in this report that purified E2A helix-loop-helix (HLH) proteins spontaneously form homodimers that are linked by an intermolecular disulfide bond. These homodimers bind DNA at physiological temperatures but fail to associate with either Id or MyoD. When the disulfide bond is reduced by an activity present in muscle cell lysates or disrupted by site-directed mutagenesis, the monomeric form of the protein is strongly favored at 37 degrees C. These E2A monomers cannot bind DNA but heterodimerize efficiently with Id and MyoD. It is also shown that an intermolecular disulfide bond cross-links E2A homodimers in B cells but not in muscle cells in which only heterodimers have been detected. These results suggest a novel mechanism for regulating the dimerization status and DNA binding properties of E2A HLH transcription factors.
More Related Videos
Related Concept Videos
Mismatch Repair
Fixing Double-strand Breaks
Homologous Recombination
Protein Modifications in the RER
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Single-Strand DNA Binding Proteins
Mismatch Repair
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...

