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

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In R-R-G-A-I serine is been replaced by alanine

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In R-R-G-A-I serine is been replaced by alanine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