The Structural Differences between a Glycoprotein Specific F-Box Protein Fbs1 and Its Homologous Protein FBG3.
PLoS One
; 10(10): e0140366, 2015.
Article
em En
| MEDLINE
| ID: mdl-26460611
The Skp1-Cul1-F-box protein (SCF) complex catalyzes protein ubiquitination in diverse cellular processes and is one of the best-characterized ubiquitin ligases. F-box proteins determine the substrate specificities of SCF ubiquitin ligases. Among these, Fbs1/FBG1/FBXO2, Fbs2/FBG2/FBXO6, and Fbs3/FBG5/FBXO27 recognize the N-glycans of glycoproteins, whereas FBG3/FBXO44 has no sugar-binding activity, despite the high sequence homology and conservation of the residues necessary for oligosaccharide binding between Fbs1-3 and FBG3. Here we determined the crystal structure of the Skp1-FBG3 complex at a resolution of 2.6 Å. The substrate-binding domain of FBG3 is composed of a 10-stranded antiparallel ß-sandwich with three helices. Although the overall structure of FBG3 is similar to that of Fbs1, the residues that form the Fbs1 carbohydrate-binding pocket failed to be superposed with the corresponding residues of FBG3. Structure-based mutational analysis shows that distinct hydrogen bond networks of four FBG3 loops, i.e., ß2-ß3, ß5-ß6, ß7-ß8, and ß9-ß10, prevent the formation of the carbohydrate-binding pocket shown in Fbs1.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glicoproteínas
/
Proteínas de Ciclo Celular
/
Proteínas F-Box
/
Proteínas do Tecido Nervoso
Limite:
Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article