Interaction of the tail with the catalytic region of a class II E2 conjugating enzyme.

摘要: Ubiquitination plays an important role in many biological processes, including DNA repair, cell cycle regulation, and protein degradation. In the latter pathway ubiquitin-conjugating enzymes or E2 are proteins forming a key E2-ubiquitin thiolester prior to substrate labelling. While structure of 150-residue catalytic domain has been well characterized, subset (class II) carry variable length C-terminal `tail' where structural detail is not available. The presence this extension target recognition, ubiquitin chain assembly oligomerization. work NMR spectroscopy was used determine secondary 215-residue yeast Ubc1 interactions its C-terminus with domain. tail found contain three α-helices between residues D169-S176, K183-L193 N203-L213 providing first evidence for well-defined region. Chemical shift mapping indicated that L2 loop were most affected indicating likely interacts This site interaction distinct from observed may act protect C88 residue direct intermediate.