title: Crystal structure of a phosphorylation-coupled saccharide transporter.
abstract: Saccharides have a central role in the nutrition of all living organisms. Whereas several saccharide uptake systems are shared between the different phylogenetic kingdoms, the phosphoenolpyruvate-dependent phosphotransferase system exists almost exclusively in bacteria. This multi-component system includes an integral membrane protein EIIC that transports saccharides and assists in their phosphorylation. Here we present the crystal structure of an EIIC from Bacillus cereus that transports diacetylchitobiose. The EIIC is a homodimer, with an expansive interface formed between the amino-terminal halves of the two protomers. The carboxy-terminal half of each protomer has a large binding pocket that contains a diacetylchitobiose, which is occluded from both sides of the membrane with its site of phosphorylation near the conserved His250 and Glu334 residues. The structure shows the architecture of this important class of transporters, identifies the determinants of substrate binding and phosphorylation, and provides a framework for understanding the mechanism of sugar translocation.
authors.affiliation: Department of Physiology & Cellular Biophysics, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, New York 10032, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cao
authors.forename: Xiangshu
authors.initials: X
authors.lastname: Jin
authors.forename: Elena J
authors.initials: EJ
authors.lastname: Levin
authors.forename: Hua
authors.initials: H
authors.lastname: Huang
authors.forename: Yinong
authors.initials: Y
authors.lastname: Zong
authors.forename: Matthias
authors.initials: M
authors.lastname: Quick
authors.forename: Jun
authors.initials: J
authors.lastname: Weng
authors.forename: Yaping
authors.initials: Y
authors.lastname: Pan
authors.forename: James
authors.initials: J
authors.lastname: Love
authors.forename: Marco
authors.initials: M
authors.lastname: Punta
authors.forename: Burkhard
authors.initials: B
authors.lastname: Rost
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Hendrickson
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Javitch
authors.forename: Kanagalaghatta R
authors.initials: KR
authors.lastname: Rajashankar
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
mesh_terms: D001409:Bacillus cereus / Q000201:enzymology*; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D003460:Crystallization; D026901:Membrane Transport Proteins / Q000737:chemistry*; D008958:Models, Molecular; D010766:Phosphorylation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D026901:Membrane Transport Proteins