Which of the following is a characteristic of calmodulin?
A)It contains only 1 helix-loop-helix motif that binds the Ca²⁺ ion.
B)Its conformation is sensitive to Ca²⁺ binding.
C)It contains a basic amphiphilic alpha helix that interacts with target proteins.
D)It modulates the activity of only protein kinase A.

Question

Quizplus · Accepted Answer

Calmodulin's conformation is sensitive to Ca²⁺ binding, as it undergoes a conformational change upon binding to Ca²⁺ allowing it to interact with target proteins. Option A is incorrect as calmodulin contains four EF-hand motifs, each containing a helix-loop-helix structure that binds Ca²⁺. Option C is partially correct, as calmodulin does contain a basic amphiphilic alpha helix, but it also has other domains involved in target protein binding. Option D is incorrect as calmodulin modulates the activity of a variety of proteins, not just protein kinase A.

Which of the Following Is a Characteristic of Calmodulin