Question

The substrate sequence recognized by protein kinase A (PKA) is R-R-G-S-I. The pseudosubstrate sequence found within the regulatory domains of PKA is R-R-G-A-I. Draw each sequence as a peptide. Describe the role of each amino acid (in both sequences).

Answer 1

Answer:

The guanidine group of the first two arginine forms a pair of ions, by which salt bridge is formed

Glycine In both sequence, act as non-polar amino acid and two leucine of enzymes will form  a hydrophobic groove. isoleucine fits into the hydrophobic groove.

In R-R-G-S-I  serine is phosphorylated by an active catalytic subunit .

In R-R-G-A-I serine is  been replaced by alanine

Explanation:

The role of the each amino acids

The guanidine group of the first two arginine forms a pair of ions, by which salt bridge is formed

Glycine In both sequence, act as non-polar amino acid and two leucine of enzymes will form  a hydrophobic groove. isoleucine fits into the hydrophobic groove.

In R-R-G-S-I  serine is phosphorylated by an active catalytic subunit .

In R-R-G-A-I serine is  been replaced by alanine

Attached below is the sequence as a peptide .