The mechanism of linkage-specific ubiquitin chain elongation by a single-subunit E2.
Cell
; 144(5): 769-81, 2011 Mar 04.
Article
em En
| MEDLINE
| ID: mdl-21376237
ABSTRACT
Ubiquitin chains of different topologies trigger distinct functional consequences, including protein degradation and reorganization of complexes. The assembly of most ubiquitin chains is promoted by E2s, yet how these enzymes achieve linkage specificity is poorly understood. We have discovered that the K11-specific Ube2S orients the donor ubiquitin through an essential noncovalent interaction that occurs in addition to the thioester bond at the E2 active site. The E2-donor ubiquitin complex transiently recognizes the acceptor ubiquitin, primarily through electrostatic interactions. The recognition of the acceptor ubiquitin surface around Lys11, but not around other lysines, generates a catalytically competent active site, which is composed of residues of both Ube2S and ubiquitin. Our studies suggest that monomeric E2s promote linkage-specific ubiquitin chain formation through substrate-assisted catalysis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ubiquitina
/
Enzimas de Conjugação de Ubiquitina
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article