The Structure of a Sugar Transporter of the Glucose EIIC Superfamily Provides Insight into the Elevator Mechanism of Membrane Transport
| Autor: | Jason G. McCoy, Ming Zhou, Wonpil Im, Jumin Lee, Sébastien F. Poget, Zhenning Ren, Sharmistha Mitra, Elena J. Levin, Vitali Stanevich, Matthias Quick |
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| Rok vydání: | 2016 |
| Předmět: |
Models
Molecular 0301 basic medicine Biology Crystallography X-Ray Article Substrate Specificity Phosphotransferase 03 medical and health sciences Bacterial Proteins Protein Domains Structural Biology Transferase Sugar transporter Molecular Biology Binding Sites Cell Membrane Membrane Transport Proteins Transporter Periplasmic space Carbohydrate Membrane transport Protein Transport Glucose 030104 developmental biology Biochemistry Carbohydrate Metabolism Phosphoenolpyruvate carboxykinase Protein Binding |
| Zdroj: | Structure. 24:956-964 |
| ISSN: | 0969-2126 |
| Popis: | The phosphoenolpyruvate:carbohydrate phosphotransferase systems are found in bacteria, where they play central roles in sugar uptake and regulation of cellular uptake processes. Little is known about how the membrane-embedded components (EIICs) selectively mediate the passage of carbohydrates across the membrane. Here we report the functional characterization and 2.55-Å resolution structure of a maltose transporter, bcMalT, belonging to the glucose superfamily of EIIC transporters. bcMalT crystallized in an outward-facing occluded conformation, in contrast to the structure of another glucose superfamily EIIC, bcChbC, which crystallized in an inward-facing occluded conformation. The structures differ in the position of a structurally conserved substrate-binding domain that is suggested to play a central role in sugar transport. In addition, molecular dynamics simulations suggest a potential pathway for substrate entry from the periplasm into the bcMalT substrate-binding site. These results provide a mechanistic framework for understanding substrate recognition and translocation for the glucose superfamily EIIC transporters. |
| Databáze: | OpenAIRE |
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