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.

Abstract

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 (β1, β2-β3, β3-β4, β5-β6, β7-β8 and β9-β10) 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.

Keywords: F-box protein; Fbs1; SCF E3 ubiquitin ligase; glycoproteins; sequence–structure relationship.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Cell Cycle Proteins / chemistry*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • F-Box Proteins / chemistry*
  • F-Box Proteins / genetics
  • F-Box Proteins / metabolism
  • Gene Expression
  • Humans
  • Hydrogen Bonding
  • Models, Molecular
  • Mutation
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Plasmids / chemistry*
  • Plasmids / metabolism
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • SKP Cullin F-Box Protein Ligases / chemistry*
  • SKP Cullin F-Box Protein Ligases / genetics
  • SKP Cullin F-Box Protein Ligases / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Structure-Activity Relationship
  • Substrate Specificity

Substances

  • Cell Cycle Proteins
  • F-Box Proteins
  • FBXO2 protein, human
  • Nerve Tissue Proteins
  • Recombinant Proteins
  • SKP Cullin F-Box Protein Ligases