6BVG
Crystal structure of bcMalT T280C-E54C crosslinked by divalent mercury
Summary for 6BVG
| Entry DOI | 10.2210/pdb6bvg/pdb |
| Related PRD ID | PRD_900001 |
| Descriptor | Protein-N(Pi)-phosphohistidine-sugar phosphotransferase (Enzyme II of the phosphotransferase system) (PTS system glucose-specific IIBC component), alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, MERCURY (II) ION (3 entities in total) |
| Functional Keywords | eiic maltose transporter, transport protein |
| Biological source | Bacillus cereus (strain ZK / E33L) |
| Total number of polymer chains | 2 |
| Total formula weight | 98726.70 |
| Authors | |
| Primary citation | Ren, Z.,Lee, J.,Moosa, M.M.,Nian, Y.,Hu, L.,Xu, Z.,McCoy, J.G.,Ferreon, A.C.M.,Im, W.,Zhou, M. Structure of an EIIC sugar transporter trapped in an inward-facing conformation. Proc. Natl. Acad. Sci. U.S.A., 115:5962-5967, 2018 Cited by PubMed Abstract: The phosphoenolpyruvate-dependent phosphotransferase system (PTS) transports sugar into bacteria and phosphorylates the sugar for metabolic consumption. The PTS is important for the survival of bacteria and thus a potential target for antibiotics, but its mechanism of sugar uptake and phosphorylation remains unclear. The PTS is composed of multiple proteins, and the membrane-embedded Enzyme IIC (EIIC) component transports sugars across the membrane. Crystal structures of two members of the glucose superfamily of EIICs, bcChbC and bcMalT, were solved in the inward-facing and outward-facing conformations, and the structures suggest that sugar translocation could be achieved by movement of a structured domain that contains the sugar-binding site. However, different conformations have not been captured on the same transporter to allow precise description of the conformational changes. Here we present a crystal structure of bcMalT trapped in an inward-facing conformation by a mercury ion that bridges two strategically placed cysteine residues. The structure allows direct comparison of the outward- and inward-facing conformations and reveals a large rigid-body motion of the sugar-binding domain and other conformational changes that accompany the rigid-body motion. All-atom molecular dynamics simulations show that the inward-facing structure is stable with or without the cross-linking. The conformational changes were further validated by single-molecule Föster resonance energy transfer (smFRET). Combined, these results establish the elevator-type mechanism of transport in the glucose superfamily of EIIC transporters. PubMed: 29784777DOI: 10.1073/pnas.1800647115 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.2 Å) |
Structure validation
Download full validation report
