An example is between D,D-peptidase (involved in building bacterial cell wall) and beta-lactamase (involved in antibiotic resistance
It is hypothesized that beta-lactamase enzyme and D,D-peptidase evolved from same ancestral protein. Hence, the homology of the amino acid sequence. Beta-lactamase can be seen as the opposite of D,D-peptidase. While D,D-peptidase is involved in cell wall building activity, beta-lactamase is involved in inhibiting cell wall building activity.