Question

Biochemists who study protein structure and function often introduce mutations (changes) to a protein's amino acid sequence. One common change is an amino acid substitution that can creates a modified protein that can mimic (function similar to) a phosphorylated protein. Using what you know about different amino acids, which amino acid(s) would be a good choice for this change to a phosphorylated-like state? Briefly explain why.

Answer 1

Phosphorylation is an important post-translational modification that regulates the activity of several enzymes involved in the metabolism. Several amino acids can be phosphorylated by a specific group of enzymes known as kinases.
Ex: Serine, Threonine, Histidine, and tyrosine

Mostly, Serine residues in proteins are phosphorylated. Phosphorylation provides negative charge.

Phsophoserine residues are mimicked by Aspartic acid or Glutamic acid residues.
Both these amino acids (Asp and Glu) are longer than Ser and also provide negative charge.