3. (10 pоints). The figure belоw shоws а homology model for аn unchаracterized protein from Pseudomonas aeruginosa called PA0012. This protein contains 88 amino acids and is suspected to bind cyclic dimeric guanosine monophosphate (c-di-GMP), a bacterial secondary messenger important for many physiological functions. The homology model is reliable and likely represents the structure of the free, unbound protein. You can make sufficient protein labelled with 1H, 15N and 13C to do any NMR experiment we talked about in class. The N-terminus may be involved in the interaction with c-di-GMP, but it appears disordered (not structured) in the homology model. Answer the following questions about the PA0012/c-di-GMP interaction: a. (4 points). Describe an NMR-based experiment you could use to test if c-di-GMP binds PA0012? How would you know that a binding event occurred and what control experiment(s) might be useful to assess specificity?. b. (2 points). Assuming PA0012 binds c-di-GMP, how would you determine the affinity of c-di-GMP for PA0012? Be specific and include how you would analyze the NMR data c. (4 points). How would you identify which residues in the protein are involved in the ligand interaction and where the potential binding site is located on the homology model?