Which is the smallest protein?

The smallest protein described to date is the TAL protein.

Determining the "smallest protein" requires some context. Polypeptides with around 50 amino acids or fewer are often considered small proteins. There isn't a strict, universally agreed-upon definition. However, according to current research, the TAL protein, which influences the development of Drosophila melanogaster (fruit flies), is currently considered the smallest, comprising just 11 amino acids.

Here's a summary:

It's important to remember that scientific understanding is constantly evolving. New discoveries could potentially identify even smaller proteins in the future.