2lq7

Publication Abstract from PubMed

The covalent attachment of ubiquitin (Ub) and ubiquitin-like (Ubl) proteins to various eukaryotic targets plays critical roles in regulating numerous cellular processes. E1-activating enzymes are critical, because they catalyze activation of their cognate Ub/Ubl protein and are responsible for its transfer to the correct E2-conjugating enzyme(s). The activating enzyme for neural-precursor-cell-expressed developmentally downregulated 8 (NEDD8) is a heterodimer composed of APPBP1 and Uba3 subunits. The carboxyl terminal ubiquitin-like beta-grasp domain of human Uba3 (Uba3-betaGD) has been suggested as a key E2-binding site defining E2 specificity. In crystal structures of free E1 and the NEDD8-E1 complex, the E2-binding surface on the domain was missing from the electron density. However, when complexed with various E2s, this missing segment adopts a kinked alpha-helix. Here, we demonstrate that Uba3-betaGD is an independently folded domain in solution and that residues involved in E2 binding are absent from the NMR spectrum, indicating that the E2-binding surface on Uba3-betaGD interconverts between multiple conformations, analogous to a similar conformational transition observed in the E2-binding surface of SUMO E1. These results suggest that access to multiple conformational substates is an important feature of the E1-E2 interaction.

E2-binding surface on Uba3 beta-grasp domain undergoes a conformational transition.,Elgin ES, Sokmen N, Peterson FC, Volkman BF, Dag C, Haas AL Proteins. 2012 Oct;80(10):2482-7. doi: 10.1002/prot.24148. Epub 2012 Jul 31. PMID:22821745^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.