2hwg
From Proteopedia
(New page: 200px<br /><applet load="2hwg" size="450" color="white" frame="true" align="right" spinBox="true" caption="2hwg, resolution 2.7Å" /> '''Structure of phosphor...) |
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| - | [[Image:2hwg.gif|left|200px]]<br /><applet load="2hwg" size=" | + | [[Image:2hwg.gif|left|200px]]<br /><applet load="2hwg" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2hwg, resolution 2.7Å" /> | caption="2hwg, resolution 2.7Å" /> | ||
'''Structure of phosphorylated Enzyme I of the phosphoenolpyruvate:sugar phosphotransferase system'''<br /> | '''Structure of phosphorylated Enzyme I of the phosphoenolpyruvate:sugar phosphotransferase system'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Bacterial transport of many sugars, coupled to their phosphorylation, is | + | Bacterial transport of many sugars, coupled to their phosphorylation, is carried out by the phosphoenolpyruvate (PEP):sugar phosphotransferase system and involves five phosphoryl group transfer reactions. Sugar translocation initiates with the Mg(2+)-dependent phosphorylation of enzyme I (EI) by PEP. Crystals of Escherichia coli EI were obtained by mixing the protein with Mg(2+) and PEP, followed by oxalate, an EI inhibitor. The crystal structure reveals a dimeric protein where each subunit comprises three domains: a domain that binds the partner PEP:sugar phosphotransferase system protein, HPr; a domain that carries the phosphorylated histidine residue, His-189; and a PEP-binding domain. The PEP-binding site is occupied by Mg(2+) and oxalate, and the phosphorylated His-189 is in-line for phosphotransfer to/from the ligand. Thus, the structure represents an enzyme intermediate just after phosphotransfer from PEP and before a conformational transition that brings His-189 approximately P in proximity to the phosphoryl group acceptor, His-15 of HPr. A model of this conformational transition is proposed whereby swiveling around an alpha-helical linker disengages the His domain from the PEP-binding domain. Assuming that HPr binds to the HPr-binding domain as observed by NMR spectroscopy of an EI fragment, a rotation around two linker segments orients the His domain relative to the HPr-binding domain so that His-189 approximately P and His-15 are appropriately stationed for an in-line phosphotransfer reaction. |
==About this Structure== | ==About this Structure== | ||
| - | 2HWG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with MG and OXL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphoenolpyruvate--protein_phosphotransferase Phosphoenolpyruvate--protein phosphotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.3.9 2.7.3.9] Full crystallographic information is available from [http:// | + | 2HWG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=OXL:'>OXL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphoenolpyruvate--protein_phosphotransferase Phosphoenolpyruvate--protein phosphotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.3.9 2.7.3.9] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HWG OCA]. |
==Reference== | ==Reference== | ||
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[[Category: pts]] | [[Category: pts]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:46:30 2008'' |
Revision as of 15:46, 21 February 2008
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Structure of phosphorylated Enzyme I of the phosphoenolpyruvate:sugar phosphotransferase system
Overview
Bacterial transport of many sugars, coupled to their phosphorylation, is carried out by the phosphoenolpyruvate (PEP):sugar phosphotransferase system and involves five phosphoryl group transfer reactions. Sugar translocation initiates with the Mg(2+)-dependent phosphorylation of enzyme I (EI) by PEP. Crystals of Escherichia coli EI were obtained by mixing the protein with Mg(2+) and PEP, followed by oxalate, an EI inhibitor. The crystal structure reveals a dimeric protein where each subunit comprises three domains: a domain that binds the partner PEP:sugar phosphotransferase system protein, HPr; a domain that carries the phosphorylated histidine residue, His-189; and a PEP-binding domain. The PEP-binding site is occupied by Mg(2+) and oxalate, and the phosphorylated His-189 is in-line for phosphotransfer to/from the ligand. Thus, the structure represents an enzyme intermediate just after phosphotransfer from PEP and before a conformational transition that brings His-189 approximately P in proximity to the phosphoryl group acceptor, His-15 of HPr. A model of this conformational transition is proposed whereby swiveling around an alpha-helical linker disengages the His domain from the PEP-binding domain. Assuming that HPr binds to the HPr-binding domain as observed by NMR spectroscopy of an EI fragment, a rotation around two linker segments orients the His domain relative to the HPr-binding domain so that His-189 approximately P and His-15 are appropriately stationed for an in-line phosphotransfer reaction.
About this Structure
2HWG is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Phosphoenolpyruvate--protein phosphotransferase, with EC number 2.7.3.9 Full crystallographic information is available from OCA.
Reference
Structure of phosphorylated enzyme I, the phosphoenolpyruvate:sugar phosphotransferase system sugar translocation signal protein., Teplyakov A, Lim K, Zhu PP, Kapadia G, Chen CC, Schwartz J, Howard A, Reddy PT, Peterkofsky A, Herzberg O, Proc Natl Acad Sci U S A. 2006 Oct 31;103(44):16218-23. Epub 2006 Oct 19. PMID:17053069
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