Nucleic acids and chromatin
Nucleic acids and chromatin

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Nucleic acids and chromatin

6.2 Non-covalent bonding in site-specific binding

The affinity of a protein for DNA is determined in thermodynamic terms by the free energies of the individual components compared to the free energy of the DNA-protein complex. DNA binding proteins, which contain different binding motifs, demonstrate a wide range of thermodynamic strategies.

The affinity of a site-specific DNA binding protein for its specific DNA sequence is generally of the order of 104−107 times greater than its affinity for non-specific sequences. Stable protein–DNA interactions arise from the combination of non-covalent interactions that we have seen in other macromolecules: hydrogen bonding, electrostatic interactions, hydrophobic interactions and van der Waals forces. These interactions can occur between protein side-chain groups and either the DNA deoxyribose-phosphate backbone or the bases. There are many types of proteins that interact with DNA, both specifically and non-specifically. Below we will briefly consider examples of how each of these types of interaction occurs, to illustrate the principles involved.

S377_1

Take your learning further371

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses372.

If you are new to university level study, we offer two introductory routes to our qualifications. Find out Where to take your learning next?373 You could either choose to start with an Access courses374or an open box module, which allows you to count your previous learning towards an Open University qualification.

Not ready for University study then browse over 1000 free courses on OpenLearn375 and sign up to our newsletter376 to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371