Question

Transcription factors need to have an attraction to DNA in order to stay near or on the DNA the majority of the time. If transcription factors were not attracted to DNA they may float off the DNA and diffuse away. In order to keep transcription factors associated with the DNA, what functional groups on proteins and on DNA may be involved in this attraction?

Answer 1

Step-by-step explanation:

DNA-protein interactions occurs at both the minor and major grooves of the DNA helix.

• The interactions involved include hydrogen bonding, Van der Waals and electrostatic interactions.
• Major groove: one hydrogen bond donor (NH+) and two hydrogen bond acceptor (COO- and purine nitrogens) groups available from the nucleotide base pairings (A.T; T.A; G.C and C.G). The Thymine has a methyl group (CH3) that participates in Van der Waals interactions.
• Minor groove: two hydrogen bond acceptor groups and one hydrogen bond donor on all four nucleotide pairs.
• Glutamine and asparagine can hydrogen bond with adenine. Guanidium nitrogens of arginine can hydrogen bond with guanine at N7 and O6 positions.