Lecture 4: solving protein structures

Question 1

X-ray crystallography [pros & cons]

Answer 1

• not limited by protein size
• capable of very high-res structures
  //
• requires protein crystals
• normally only “sees” a single conformation

Question 2

NMR [pros & cons]

Answer 2

• captures multiple conformations
• captures weak protein-protein or protein-ligand information
• no need for crystals
  //
• needs isotope labeling
• limited by protein size [good for small proteins]

Question 3

Cryogenic electronic microscopy (cryo-EM) [pros & cons]

Answer 3

• works well for large complexes
• no need for crystals
  //
• does not work well for small proteins
• limited by resolution structures [low res.]

Question 4

Protein structure prediction [pros & cons]

Answer 4

• no lab-bench work needed
• can be done quickly
  //
• limited by the size of the database
• model still needs validation by empirical data

Question 5

most commonly used method for protein structure identification

Answer 5

x-ray