Cryo-EM structure of arabinosyltransferase EmbB from Mycobacterium smegmatis

Nat Commun. 2020 Jul 7;11(1):3396. doi: 10.1038/s41467-020-17202-8.


Arabinosyltransferase B (EmbB) belongs to a family of membrane-bound glycosyltransferases that build the lipidated polysaccharides of the mycobacterial cell envelope, and are targets of anti-tuberculosis drug ethambutol. We present the 3.3 Å resolution single-particle cryo-electron microscopy structure of Mycobacterium smegmatis EmbB, providing insights on substrate binding and reaction mechanism. Mutations that confer ethambutol resistance map mostly around the putative active site, suggesting this to be the location of drug binding.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antitubercular Agents / pharmacology
  • Catalytic Domain
  • Cryoelectron Microscopy
  • Drug Resistance, Bacterial
  • Ethambutol / pharmacology
  • Lipids / chemistry
  • Mutation
  • Mycobacterium smegmatis / enzymology*
  • Mycobacterium tuberculosis / enzymology
  • Pentosyltransferases / chemistry*
  • Pentosyltransferases / ultrastructure*
  • Polysaccharides / chemistry
  • Protein Binding


  • Antitubercular Agents
  • Lipids
  • Polysaccharides
  • Ethambutol
  • EmbB protein, Mycobacterium tuberculosis
  • Pentosyltransferases