UbiquitinPDB ID: 1UBQ
A chain of ubiquitin molecules are added to obsolete proteins, indicating that they need to be destroyed. This structure includes a single ubiquitin molecule.
Discussed Structures from Ubiquitin
Vijay-Kumar, S., Bugg, C.E., Cook, W.J. (1987) Structure of ubiquitin refined at 1.8 A resolution. J Mol Biol 194: 531-44