Crystal structure of the Ube2K/E2-25K and K48-linked di-ubiquitin complex provides structural insight into the mechanism of K48-specific ubiquitin chain synthesis.
Biochem Biophys Res Commun
; 506(1): 102-107, 2018 11 17.
Article
em En
| MEDLINE
| ID: mdl-30336976
ABSTRACT
Ubiquitin-conjugating enzymes (E2) form thioester bonds with ubiquitin (Ub), which are subsequently transferred to target proteins for cellular progress. Ube2K/E2-25K (a class II E2 enzyme) contains a C-terminal ubiquitin-associated (UBA) domain that has been suggested to control ubiquitin recognition, dimerization, or poly-ubiquitin chain formation. Ube2K is a special E2 because it synthesizes K48-linked poly-ubiquitin chains without E3 ubiquitin ligase. We found that a novel interaction between the acceptor di-Ub (Ub2) and the auxiliary Ube2K promotes the discharging reaction and production of tri-Ub (Ub3), probably by guiding and positioning the K48 (in the distal Ub) of the acceptor Ub2 in the active site. We also determined the crystal structure of Ube2K-Ub2 at 2.47â¯Å resolution. Based on our structural and biochemical data, we proposed a structural model of Ub3 synthesis by Ube2K without E3.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ubiquitinas
/
Enzimas Ativadoras de Ubiquitina
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Enzimas de Conjugação de Ubiquitina
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Lisina
Limite:
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
2018
Tipo de documento:
Article