What Is Ubiquitin Protein?

Ubiquitin is a small protein found in all eukaryotes (mostly eukaryotic cells). Ubiquitin consists of 76 amino acids and has a molecular weight of approximately 8,500 Daltons. Its main function is to label the proteins that need to be broken down so that they are degraded by the 26S proteasome. Some receptors on the regulatory subunits of the 26S proteasome can recognize K48 and K11-linked polyubiquitinated proteins, and the 20S core subunit hydrolyzes substrates under ATPase energy. ^[1]