1ueh
From Proteopedia
(New page: 200px<br /><applet load="1ueh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ueh, resolution 1.73Å" /> '''E. coli undecaprenyl...) |
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| - | [[Image:1ueh.jpg|left|200px]]<br /><applet load="1ueh" size=" | + | [[Image:1ueh.jpg|left|200px]]<br /><applet load="1ueh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ueh, resolution 1.73Å" /> | caption="1ueh, resolution 1.73Å" /> | ||
'''E. coli undecaprenyl pyrophosphate synthase in complex with Triton X-100, magnesium and sulfate'''<br /> | '''E. coli undecaprenyl pyrophosphate synthase in complex with Triton X-100, magnesium and sulfate'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Undecaprenyl pyrophosphate synthase (UPPs) catalyzes chain elongation of | + | Undecaprenyl pyrophosphate synthase (UPPs) catalyzes chain elongation of farnesyl pyrophosphate (FPP) to undecaprenyl pyrophosphate (UPP) via condensation with eight isopentenyl pyrophosphates (IPP). UPPs from Escherichia coli is a dimer, and each subunit consists of 253 amino acid residues. The chain length of the product is modulated by a hydrophobic active site tunnel. In this paper, the crystal structure of E. coli UPPs was refined to 1.73 A resolution, which showed bound sulfate and magnesium ions as well as Triton X-100 molecules. The amino acid residues 72-82, which encompass an essential catalytic loop not seen in the previous apoenzyme structure (Ko, T.-P., Chen, Y. K., Robinson, H., Tsai, P. C., Gao, Y.-G., Chen, A. P.-C., Wang, A. H.-J., and Liang, P.-H. (2001) J. Biol. Chem. 276, 47474-47482), also became visible in one subunit. The sulfate ions suggest locations of the pyrophosphate groups of FPP and IPP in the active site. The Mg2+ is chelated by His-199 and Glu-213 from different subunits and possibly plays a structural rather than catalytic role. However, the metal ion is near the IPP-binding site, and double mutation of His-199 and Glu-213 to alanines showed a remarkable increase of Km value for IPP. Inside the tunnel, one Triton surrounds the top portion of the tunnel, and the other occupies the bottom part. These two Triton molecules may mimic the hydrocarbon moiety of the UPP product in the active site. Kinetic analysis indicated that a high concentration (>1%) of Triton inhibits the enzyme activity. |
==About this Structure== | ==About this Structure== | ||
| - | 1UEH 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 SO4, MG, OXN and UNK as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Di-trans,poly-cis-decaprenylcistransferase Di-trans,poly-cis-decaprenylcistransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.31 2.5.1.31] Full crystallographic information is available from [http:// | + | 1UEH 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=SO4:'>SO4</scene>, <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=OXN:'>OXN</scene> and <scene name='pdbligand=UNK:'>UNK</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Di-trans,poly-cis-decaprenylcistransferase Di-trans,poly-cis-decaprenylcistransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.31 2.5.1.31] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UEH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chang, S | + | [[Category: Chang, S Y.]] |
| - | [[Category: Ko, T | + | [[Category: Ko, T P.]] |
| - | [[Category: Liang, P | + | [[Category: Liang, P H.]] |
| - | [[Category: Wang, A | + | [[Category: Wang, A H.J.]] |
[[Category: MG]] | [[Category: MG]] | ||
[[Category: OXN]] | [[Category: OXN]] | ||
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[[Category: rossmann-like fold]] | [[Category: rossmann-like fold]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:23:37 2008'' |
Revision as of 13:23, 21 February 2008
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E. coli undecaprenyl pyrophosphate synthase in complex with Triton X-100, magnesium and sulfate
Overview
Undecaprenyl pyrophosphate synthase (UPPs) catalyzes chain elongation of farnesyl pyrophosphate (FPP) to undecaprenyl pyrophosphate (UPP) via condensation with eight isopentenyl pyrophosphates (IPP). UPPs from Escherichia coli is a dimer, and each subunit consists of 253 amino acid residues. The chain length of the product is modulated by a hydrophobic active site tunnel. In this paper, the crystal structure of E. coli UPPs was refined to 1.73 A resolution, which showed bound sulfate and magnesium ions as well as Triton X-100 molecules. The amino acid residues 72-82, which encompass an essential catalytic loop not seen in the previous apoenzyme structure (Ko, T.-P., Chen, Y. K., Robinson, H., Tsai, P. C., Gao, Y.-G., Chen, A. P.-C., Wang, A. H.-J., and Liang, P.-H. (2001) J. Biol. Chem. 276, 47474-47482), also became visible in one subunit. The sulfate ions suggest locations of the pyrophosphate groups of FPP and IPP in the active site. The Mg2+ is chelated by His-199 and Glu-213 from different subunits and possibly plays a structural rather than catalytic role. However, the metal ion is near the IPP-binding site, and double mutation of His-199 and Glu-213 to alanines showed a remarkable increase of Km value for IPP. Inside the tunnel, one Triton surrounds the top portion of the tunnel, and the other occupies the bottom part. These two Triton molecules may mimic the hydrocarbon moiety of the UPP product in the active site. Kinetic analysis indicated that a high concentration (>1%) of Triton inhibits the enzyme activity.
About this Structure
1UEH is a Single protein structure of sequence from Escherichia coli with , , and as ligands. Active as Di-trans,poly-cis-decaprenylcistransferase, with EC number 2.5.1.31 Full crystallographic information is available from OCA.
Reference
Catalytic mechanism revealed by the crystal structure of undecaprenyl pyrophosphate synthase in complex with sulfate, magnesium, and triton., Chang SY, Ko TP, Liang PH, Wang AH, J Biol Chem. 2003 Aug 1;278(31):29298-307. Epub 2003 May 19. PMID:12756244
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