Solution NMR structure and functional analysis of the integral membrane protein YgaP from Escherichia coli

J Biol Chem. 2014 Aug 22;289(34):23482-503. doi: 10.1074/jbc.M114.571935. Epub 2014 Jun 23.


The solution NMR structure of the α-helical integral membrane protein YgaP from Escherichia coli in mixed 1,2-diheptanoyl-sn-glycerol-3-phosphocholine/1-myristoyl-2-hydroxy-sn-glycero-3-phospho-(1'-rac-glycerol) micelles is presented. In these micelles, YgaP forms a homodimer with the two transmembrane helices being the dimer interface, whereas the N-terminal cytoplasmic domain includes a rhodanese-fold in accordance to its sequence homology to the rhodanese family of sulfurtransferases. The enzymatic sulfur transfer activity of full-length YgaP as well as of the N-terminal rhodanese domain only was investigated performing a series of titrations with sodium thiosulfate and potassium cyanide monitored by NMR and EPR. The data indicate the thiosulfate concentration-dependent addition of several sulfur atoms to the catalytic Cys-63, which process can be reversed by the addition of potassium cyanide. The catalytic reaction induces thereby conformational changes within the rhodanese domain, as well as on the transmembrane α-helices of YgaP. These results provide insights into a potential mechanism of YgaP during the catalytic thiosulfate activity in vivo.

Keywords: Enzyme Catalysis; Membrane Enzyme; Membrane Protein; Nuclear Magnetic Resonance (NMR); Rhodanese; Structural Biology; Sulfotransferase; Sulfurtransferase; Three-dimensional Structure.

MeSH terms

  • Escherichia coli / chemistry*
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / physiology*
  • Membrane Proteins / chemistry*
  • Membrane Proteins / physiology*
  • Models, Molecular
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Protein Conformation
  • Structure-Activity Relationship
  • Thiosulfate Sulfurtransferase / chemistry


  • Escherichia coli Proteins
  • Membrane Proteins
  • YgaP protein, E coli
  • Thiosulfate Sulfurtransferase

Associated data

  • PDB/2MOI
  • PDB/2MOL
  • PDB/2MPN