6BVG

Crystal structure of bcMalT T280C-E54C crosslinked by divalent mercury

6BVG の概要

• エントリーDOI: 10.2210/pdb6bvg/pdb
• 関連するBIRD辞書のPRD_ID: PRD_900001
• 分子名称: 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)
• 機能のキーワード: eiic maltose transporter, transport protein
• 由来する生物種: Bacillus cereus (strain ZK / E33L)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 98726.70

構造登録者

Ren, Z.,Zhou, M. (登録日: 2017-12-12, 公開日: 2018-05-23, 最終更新日: 2023-10-04)

主引用文献

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

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: 29784777
DOI: 10.1073/pnas.1800647115

実験手法

X-RAY DIFFRACTION (3.2 Å)