* Lysine (Lys, K): Lysine has a positively charged amino group (NH3+) in its side chain.
* Glutamic acid (Glu, E): Glutamic acid has a negatively charged carboxyl group (COO-) in its side chain.
Why they would form an electrostatic attraction:
Opposite charges attract! The positively charged side chain of lysine would be attracted to the negatively charged side chain of glutamic acid. This type of interaction is called a salt bridge or ionic bond.
Important Note: This attraction would be most likely to occur when the amino acids are in close proximity to each other within a protein structure.
