Ubiquitin is considered one of the most highly conserved eukaryotic proteins. A remarkable 72 out of 76 amino acid residues are invariant in the ubiquitins of fungi, plants and vertebrates. To date, the ubiquitin sequences of only two fungi have been reported, those of Sacchoromyces cerevisiae (1) and Neurospora crassa (2). These fungi are both ascomycetes, and not surprisingly their ubiquitin ...
