Functional and physical characterization of the cell cycle ubiquitin-conjugating enzyme CDC34 (UBC3). Identification of a functional determinant within the tail that facilitates CDC34 self-association.

摘要: Like several other ubiquitin-conjugating enzymes, the yeast cell cycle enzyme CDC34 (UBC3) has a carboxyl-terminal extension or tail. These tails appear to carry out unique functions that can vary from one next. Using biophysical techniques we have determined tail of constitutes highly structured and extended domain. Although is largest identified date (125 residues), found only 39 residues lying adjacent catalytic domain are necessary sufficient for full function this region fulfills novel may be common enzymes. Cross-linking studies demonstrate facilitates physical interaction between monomers in vitro. Furthermore, phenotypic analysis various derivatives expressed different cdc34 mutant strains indicates same vivo. Based on these findings, it appears dependent upon ability interact with another mediated by small The similarity sequences contained within UBC1 UBC6 enzymes suggests similar manner.