Question

Why might more transcription factors bind to the major groove of DNA rather than the minor groove of DNA? Discuss in terms of ability to recognize specific DNA sequences.

Answer 1

The strand backbones are closer together on one side of the helix than on the other. The major groove occurs where the backbones are far apart, the minor groove occurs where they are close together. The grooves twist around the molecule on opposite sides. Certain proteins bind to DNA to alter its structure or to regulate transcription (copying DNA to RNA) or replication (copying DNA to DNA). It is easier for these DNA binding proteins to interact with the bases (the internal parts of the DNA molecule) on the major groove side because the backbones are not in the way.

major grooves and minor grooves

These grooves are important because proteins that interact with DNA often recognize a particular sequence of bases by making contact with the bases via the major or minor groove or both.

The proteins that bind to DNA usually bind in the major groove due to They have residues that can hydrogen-bond to the base functional groups exposed to the major groove or positive char this is a major contributor the the stability of the double helix. Joining of nucleotides is always by the 5'OH of one to the 5'OH of the other. The antiparallel arrangement permits opposing nucleotides to be in the proper position to form hydrogen bonds. Each pair in hydrogen bonding must be in the proper tautomeric form so that one is the donor and the other is the acceptor. The grooves are different with the major groove wider than the minor groove.ges that bind to the phosphates in the backbone.