Molecular evolution of ubiquitin genes.

Ubiquitin is a singular protein with multiple functions. It is probably the most slowly evolving protein known, is encoded by genes with a unique structure, and provides an intriguing case study for various aspects of molecular evolution. In particular, the multiple ubiquitin-coding repeats which have been characterized in man, yeast and a slime mould graphically illustrate the dynamics of concerted evolution, but cast doubts on the effectiveness of this process for unlinked arrays in this repeat family.