Structural basis of protein arginine rhamnosylation by glycosyltransferase EarP

Nat Chem Biol. 2018 Apr;14(4):368-374. doi: 10.1038/s41589-018-0002-y. Epub 2018 Feb 13.


Protein glycosylation regulates many cellular processes. Numerous glycosyltransferases with broad substrate specificities have been structurally characterized. A novel inverting glycosyltransferase, EarP, specifically transfers rhamnose from dTDP-β-L-rhamnose to Arg32 of bacterial translation elongation factor P (EF-P) to activate its function. Here we report a crystallographic study of Neisseria meningitidis EarP. The EarP structure contains two tandem Rossmann-fold domains, which classifies EarP in glycosyltransferase superfamily B. In contrast to other structurally characterized protein glycosyltransferases, EarP binds the entire β-sheet structure of EF-P domain I through numerous interactions that specifically recognize its conserved residues. Thus Arg32 is properly located at the active site, and causes structural change in a conserved dTDP-β-L-rhamnose-binding loop of EarP. Rhamnosylation by EarP should occur via an SN2 reaction, with Asp20 as the general base. The Arg32 binding and accompanying structural change of EarP may induce a change in the rhamnose-ring conformation suitable for the reaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arginine / chemistry*
  • Bacterial Proteins / metabolism*
  • Crystallography, X-Ray
  • Disulfides
  • Escherichia coli / metabolism
  • Glycosylation
  • Glycosyltransferases / metabolism*
  • Kinetics
  • Mutation
  • Neisseria meningitidis / metabolism
  • Nucleoside Diphosphate Sugars
  • Peptide Elongation Factors / metabolism*
  • Protein Binding
  • Protein Domains
  • Protein Structure, Secondary
  • Rhamnose / chemistry*
  • Thymine Nucleotides


  • Bacterial Proteins
  • Disulfides
  • Nucleoside Diphosphate Sugars
  • Peptide Elongation Factors
  • Thymine Nucleotides
  • factor EF-P
  • thymidine diphosphate rhamnose
  • Arginine
  • Glycosyltransferases
  • Rhamnose