Concept #1: Motifs and Domains

Concept #2: Protein Motifs

Practice: Which of the following colored regions in the images below is not an example of a supersecondary structure?

Concept #3: Protein Domains

Practice: Which of the following statements concerning a Cas9 endonuclease’s protein domains is true?

Practice: Which of the following is true concerning the motifs and domains of proteins?

Practice: Appropriately label the domains of the membrane embedded protein in the figure below.

Practice: The structure of an immunoglobulin G (antibody) molecule is shown schematically below. The black solid lines depict individual polypeptides and so there are four polypeptides in the quaternary structure of this molecule. Each of the spheres represents a stretch of about 100 amino acids folded independently of the rest of the polypeptide and performs a specific function in the molecule. Therefore, each sphere was given its own individual name (VH, CH1, CH2, etc.). Without knowing any additional details, you can predict that there must be TWELVE ___________________ in this molecule.

Practice: What is the main difference between an endonuclease’s domains and its subunits?