Specificity of the E1-E2-E3 enzymatic cascade for ubiquitin C-terminal sequences identified by phage display.

ABSTRACT: Ubiquitin (UB) is a protein modifier that regulates many essential cellular processes. To initiate protein modification by UB, the E1 enzyme activates the C-terminal carboxylate of UB to launch its transfer through the E1-E2-E3 cascade onto target proteins. In this study, we used phage display to profile the specificity of the two human E1 enzymes, Ube1 and Uba6, toward the C-terminal sequence of UB ending with (71)LRLRGG(76). Phage selection revealed that while Arg72 of UB is absolutely required for E1 recognition, UB residues at positions 71, 73, and 74 can be replaced with bulky aromatic side chains, and Gly75 of UB can be changed to Ser, Asp, and Asn for efficient E1 activation. We have thus found that the E1 enzymes have substantial promiscuity regarding the UB C-terminal sequence. Th

SUBMITTER: Zhao B 

PROVIDER: S-EPMC4652587 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature