Question

Two or three α helices can sometimes wrap around each other to form coiled-coils. The stable wrapping of one helix around another is typically driven by __________ interactions.

a. hydrophilic
b. hydrophobic
c. van der Waals
d. ionic

Answer 1

The stable wrapping of one alpha helix around another in protein coiled-coils is driven by hydrophobic interactions, as nonpolar amino acids with hydrophobic R groups interact within the protein's interior.

Step-by-step explanation:

The stable wrapping of one helix around another in the formation of coiled-coils in proteins is typically driven by hydrophobic interactions. These interactions occur as the hydrophobic R groups of nonpolar amino acids tend to be in the interior of the protein landscape, where they can avoid water and instead associate more closely with each other. This internal positioning allows for a stable structure that is further reinforced through additional forces such as hydrogen bonds, van der Waals forces, and ionic bonding, but the main driving force behind the stable coiling is the tendency of hydrophobic regions to minimize their exposure to the aqueous environment.