In a reversible covalent modification reaction involving the phosphorylation of a target protein,which of the following amino acids is LEAST likely to be modified with a phosphate group?
A) Ser
B) Phe
C) Tyr
D) Thr

Question

Quizplus · Accepted Answer

Phosphorylation typically occurs on Ser, Thr, and Tyr residues, as these have a hydroxyl (-OH) functional group that can be phosphorylated. Phe does not have this functional group and is not commonly phosphorylated.

In a Reversible Covalent Modification Reaction Involving the Phosphorylation of a Target