1zym
From Proteopedia
(New page: 200px<br /><applet load="1zym" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zym, resolution 2.5Å" /> '''AMINO TERMINAL DOMAIN...) |
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| - | [[Image:1zym.jpg|left|200px]]<br /><applet load="1zym" size=" | + | [[Image:1zym.jpg|left|200px]]<br /><applet load="1zym" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1zym, resolution 2.5Å" /> | caption="1zym, resolution 2.5Å" /> | ||
'''AMINO TERMINAL DOMAIN OF ENZYME I FROM ESCHERICHIA COLI'''<br /> | '''AMINO TERMINAL DOMAIN OF ENZYME I FROM ESCHERICHIA COLI'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: The bacterial phosphoenolpyruvate (PEP): sugar | + | BACKGROUND: The bacterial phosphoenolpyruvate (PEP): sugar phosphotransferase system (PTS) transports exogenous hexose sugars through the membrane and tightly couples transport with phosphoryl transfer from PEP to the sugar via several phosphoprotein intermediates. The phosphate group is first transferred to enzyme I, second to the histidine-containing phosphocarrier protein HPr, and then to one of a number of sugar-specific enzymes II. The structures of several HPrs and enzymes IIA are known. Here we report the structure of the N-terminal half of enzyme I from Escherichia coli (EIN). RESULTS: The crystal structure of EIN (MW approximately 30 kDa) has been determined and refined at 2.5 A resolution. It has two distinct structural subdomains; one contains four alpha helices arranged as two hairpins in a claw-like conformation. The other consists of a beta sandwich containing a three-stranded antiparallel beta sheet and a four-stranded parallel beta sheet, together with three short alpha helices. Plausible models of complexes between EIN and HPr can be made without assuming major structural changes in either protein. CONCLUSIONS: The alpha/beta subdomain of EIN is topologically similar to the phosphohistidine domain of the enzyme pyruvate phosphate dikinase, which is phosphorylated by PEP on a histidyl residue but does not interact with HPr. It is therefore likely that features of this subdomain are important in the autophosphorylation of enzyme I. The helical subdomain of EIN is not found in pyruvate phosphate dikinase; this subdomain is therefore more likely to be involved in phosphoryl transfer to HPr. |
==About this Structure== | ==About this Structure== | ||
| - | 1ZYM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. 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:// | + | 1ZYM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. 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=1ZYM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Phosphoenolpyruvate--protein phosphotransferase]] | [[Category: Phosphoenolpyruvate--protein phosphotransferase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Davies, D | + | [[Category: Davies, D R.]] |
| - | [[Category: Liao, D | + | [[Category: Liao, D I.]] |
[[Category: phosphotransferase]] | [[Category: phosphotransferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:20:28 2008'' |
Revision as of 14:20, 21 February 2008
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AMINO TERMINAL DOMAIN OF ENZYME I FROM ESCHERICHIA COLI
Overview
BACKGROUND: The bacterial phosphoenolpyruvate (PEP): sugar phosphotransferase system (PTS) transports exogenous hexose sugars through the membrane and tightly couples transport with phosphoryl transfer from PEP to the sugar via several phosphoprotein intermediates. The phosphate group is first transferred to enzyme I, second to the histidine-containing phosphocarrier protein HPr, and then to one of a number of sugar-specific enzymes II. The structures of several HPrs and enzymes IIA are known. Here we report the structure of the N-terminal half of enzyme I from Escherichia coli (EIN). RESULTS: The crystal structure of EIN (MW approximately 30 kDa) has been determined and refined at 2.5 A resolution. It has two distinct structural subdomains; one contains four alpha helices arranged as two hairpins in a claw-like conformation. The other consists of a beta sandwich containing a three-stranded antiparallel beta sheet and a four-stranded parallel beta sheet, together with three short alpha helices. Plausible models of complexes between EIN and HPr can be made without assuming major structural changes in either protein. CONCLUSIONS: The alpha/beta subdomain of EIN is topologically similar to the phosphohistidine domain of the enzyme pyruvate phosphate dikinase, which is phosphorylated by PEP on a histidyl residue but does not interact with HPr. It is therefore likely that features of this subdomain are important in the autophosphorylation of enzyme I. The helical subdomain of EIN is not found in pyruvate phosphate dikinase; this subdomain is therefore more likely to be involved in phosphoryl transfer to HPr.
About this Structure
1ZYM is a Single protein structure of sequence from Escherichia coli. Active as Phosphoenolpyruvate--protein phosphotransferase, with EC number 2.7.3.9 Full crystallographic information is available from OCA.
Reference
The first step in sugar transport: crystal structure of the amino terminal domain of enzyme I of the E. coli PEP: sugar phosphotransferase system and a model of the phosphotransfer complex with HPr., Liao DI, Silverton E, Seok YJ, Lee BR, Peterkofsky A, Davies DR, Structure. 1996 Jul 15;4(7):861-72. PMID:8805571
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