Protein Conjugation in PRR

Perhaps the most fascinating aspect of eukaryotic PRR is not simply how it has adapted to use protein conjugation in place of protein cleavage as in prokaryotes, but that it does so in ways that have set new precedents and revealed completely novel mechanisms in DNA repair. The following sections will describe the molecular framework behind the three protein conjugation complexes in PRR. 

On the basis of the conventional genetic hierarchy of DNA postrepUca-tion repair, as discussed above, Rad6 is considered the hallmark and starting point for the pathway. RAD6 encodes a multifunctional Ubc (Jentsch et al, 1987) that, in addition to its roles in DNA repair, functions 

The second instance of ubiquitin conjugation in PRR involves an atypical poly-Ub chain and a novel mechanism of catalysis employing a Ubc enzyme variant (Uev), Mms2. The MMS2 gene was isolated by functional 

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