Two proteins blue shapes below dimerize with each other in a

Two proteins (blue shapes below) dimerize with each other in a non-covalent manner (amino acids listed below, bonds are shown as dotted blue lines) to create a quaternary structure. The protein complex function is only active as long as the proteins interact in a noncovalent manner at these residue sites. Complete the table below and answer the following questions. Please explain how you came to these conclusions.

Interacting side chains Cys43: Cys65 Asp58:Lys75 Ser68 Gln28 Phe78 Val11 Arg87: Glu97 Cys36 Cys43 s Cys65 Ala45 Asp58 Lys75 Ser68 GIn28 Phe78 Val11 Arg87 Glu97 Type of interaction

Solution

Interacting side chains Type of interaction Cys43-cys65 Disulfide bond is formed between two cys Asp 58:Lys75 Ionic Interaction - (The carboxylic group of Asp interacts with the amino group of Lys) Ser68:Gln28 Hydrogen bond is formed between Ser and Gln phe78:Val11 Hydrophobic interaction - The non polar phenyl alanine interacts with polar valine. Arg87:Glu97 Ionic interaction - The carboxylic group of Arg interacts with the amino group of Glu)