Crystal stuctures of MglB-2 (TP0684), a topologically variant d-glucose-binding protein from Treponema pallidum, reveal a ligand-induced conformational change

Protein Sci. 2018 Apr;27(4):880-885. doi: 10.1002/pro.3373. Epub 2018 Feb 1.


Previously, we determined the crystal structure of apo-TpMglB-2, a d-glucose-binding component of a putative ABC transporter from the syphilis spirochete Treponema pallidum. The protein had an unusual topology for this class of proteins, raising the question of whether the d-glucose-binding mode would be different in TpMglB-2. Here, we present the crystal structures of a variant of TpMglB-2 with and without d-glucose bound. The structures demonstrate that, despite its aberrant topology, the protein undergoes conformational changes and binds d-glucose similarly to other Mgl-type proteins, likely facilitating d-glucose uptake in T. pallidum.

Keywords: ABC transporter; conformational change; glucose-binding protein; spirochete; syphilis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Crystallography, X-Ray
  • Glucose / metabolism
  • Models, Molecular
  • Monosaccharide Transport Proteins / chemistry*
  • Monosaccharide Transport Proteins / metabolism
  • Protein Conformation
  • Treponema pallidum / chemistry*


  • Bacterial Proteins
  • Monosaccharide Transport Proteins
  • Glucose

Associated data

  • PDB/6BGC
  • PDB/6BGD