Ubiquitin, N-terminal FLAG-tagged can replace the ubiquitin in formation of poly-ubiquitin—protein conjugates. The FLAG tag enables separation and enrichment of the protein conjugates on anti-FLAG affinity columns and detection of conjugates in western blot by anti-FLAG antibodies.
Ubiquitin, a globular protein is made of 76 amino acids and has lysine residues on its surface. It has a molecular weight of 8565 Da.
Ubiquitin interacts with the lysine residue of proteins through its ε-amino group of the C-terminal glycine residue. Proteins interacting with ubiquitin either undergo mono-ubiquitination or multi-mono-ubiquitination via a three-step process. Ubiquitination regulates intracellular trafficking and protein degradation and an imbalance in the pathway is implicated in disorders.
