Pili are made of special protein called _:

Explanation

Pili, also known as fimbriae are thin, hair-like structures found on the surface of many bacteria. They are composed of a specialized protein called pilin. Pilin proteins are assembled into filamentous structures that extend from the bacterial surface. Pili have various functions. including facilitating bacterial attachment to surfaces (such as host tissues or other bacterial cells) and participating in processes like bacterial conjugation, which involves the transfer of genetic material between bacterial cells.