PMID: 27487926
Nishio K, Yoshida Y, Tanaka K, Mizushima T
Structural analysis of a function-associated loop mutant of the substrate-recognition domain of Fbs1 ubiquitin ligase.
Acta Crystallogr F Struct Biol Commun. 2016 Aug;72(Pt 8):619-26. doi:, 10.1107/S2053230X16011018. Epub 2016 Jul 27.
The SCF ubiquitin ligase comprises four components: Skp1, Cul1, Rbx1 and a variable-subunit F-box protein. The F-box protein Fbs1, which recognizes the N-linked glycoproteins, is involved in the endoplasmic reticulum-associated degradation pathway. Although FBG3, another F-box protein, shares 51% sequence identity with Fbs1, FBG3 does not bind glycoproteins. To investigate the sequence-structure relationship of the substrate-binding pocket, the crystal structure of a mutant substrate-binding domain of Fbs1 in which the six nonconserved regions (beta1, beta2-beta3, beta3-beta4, beta5-beta6, beta7-beta8 and beta9-beta10) of Fbs1 were substituted with those of FBG3 was determined. The substrate-binding pocket of this model exhibits structural features that differ from those of Fsb1.