The A159E mutation causes an A amino acid to be replaced with an E amino acid (their structures are shown here). What effects do you think the A159E mutation will have on the troponin protein?

Due to hydrophilic nature of E amino acid, it will make it self to be exposed on protein surface and will disrupt the structure and potentially the function of troponin.

Explanation:

Since the E amino acid is hydrophilic, it will try to be exposed on the surface of the protein and thus will disrupt the tertiary structure and potentially the function of troponin.