Enzyme I of the Phosphoenolpyruvate:Sugar Phosphotransferase System: Difference between revisions
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==Enzyme I | ==Enzyme I of the PTS - a Molecular machine== | ||
<big> | |||
*[https://www.youtube.com/watch?v=qE-g6A4bH5E '''VIDEO of the PTS Enzyme in Action'''] | |||
*[https://www.youtube.com/watch?v=hxuBouGfs_4 '''VIDEO of the Pyruvate Phosphate Dikinase Enzyme in Action'''] | |||
** Video source: [https://www.ibbr.umd.edu/groups/herzberg Osnat Herzberg Group] | |||
</big> | |||
[[Image:Pts.jpg|left|thumb|'''The PTS'''|400px]]<br> | [[Image:Pts.jpg|left|thumb|'''The PTS'''|400px]]<br> | ||
Bacteria evolved a unique mechanism to import many carbohydrates, the '''phosphoenolpyruvate:sugar phosphotransferase system''' (PTS). The PTS synchronizes the transport and phosphorylation of the sugar (group translocation), engaging several proteins in a five steps phosphorylation cascade. With some variations, the PTS comprises three proteins: In the cytoplasm, PEP phosphorylates '''Enzyme I''' (EI), which then transfers the phosphoryl group to the histidine phosphocarrier protein, HPr. From HPr, the phosphoryl group is transferred to various sugar-specific membrane associated transporters (EnzII), each comprising two cytoplasmic domains, EIIA and EIIB, and an integral membrane domain EIIC. Within EII, EIIA accepts the phosphoryl group from HPr and donates it to EIIB, whereupon EIIC mediates sugar translocation with EIIB providing the phosphoryl group. In addition to controlling sugar translocation, the phosphorylation state of PTS proteins is also associated with regulation of metabolic pathways and signaling in bacterial cells.<br> | Bacteria evolved a unique mechanism to import many carbohydrates, the '''phosphoenolpyruvate:sugar phosphotransferase system''' (PTS). The PTS synchronizes the transport and phosphorylation of the sugar (group translocation), engaging several proteins in a five steps phosphorylation cascade. With some variations, the PTS comprises three proteins: In the cytoplasm, PEP phosphorylates '''Enzyme I''' (EI), which then transfers the phosphoryl group to the histidine phosphocarrier protein, HPr. From HPr, the phosphoryl group is transferred to various sugar-specific membrane associated transporters (EnzII), each comprising two cytoplasmic domains, EIIA and EIIB, and an integral membrane domain EIIC. Within EII, EIIA accepts the phosphoryl group from HPr and donates it to EIIB, whereupon EIIC mediates sugar translocation with EIIB providing the phosphoryl group. In addition to controlling sugar translocation, the phosphorylation state of PTS proteins is also associated with regulation of metabolic pathways and signaling in bacterial cells.<br> | ||
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==Additional Resources== | ==Additional Resources== | ||
[[User:Karl_Oberholser/Phosphoenolpyruvate:Sugar_Phosphotransferase|Larger movie frame]] for classroom projection <br> | |||
For additional information, see: [[Membrane Channels & Pumps]] <br /> | For additional information, see: [[Membrane Channels & Pumps]] <br /> | ||
For additional information, see: [[Photosynthesis]] | For additional information, see: [[Photosynthesis]] | ||