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1eq2
From Proteopedia
(New page: 200px<br /><applet load="1eq2" size="450" color="white" frame="true" align="right" spinBox="true" caption="1eq2, resolution 2.0Å" /> '''THE CRYSTAL STRUCTURE...) |
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| - | [[Image:1eq2.gif|left|200px]]<br /><applet load="1eq2" size=" | + | [[Image:1eq2.gif|left|200px]]<br /><applet load="1eq2" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1eq2, resolution 2.0Å" /> | caption="1eq2, resolution 2.0Å" /> | ||
'''THE CRYSTAL STRUCTURE OF ADP-L-GLYCERO-D-MANNOHEPTOSE 6-EPIMERASE'''<br /> | '''THE CRYSTAL STRUCTURE OF ADP-L-GLYCERO-D-MANNOHEPTOSE 6-EPIMERASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: ADP-L-glycero--mannoheptose 6-epimerase (AGME) is required for | + | BACKGROUND: ADP-L-glycero--mannoheptose 6-epimerase (AGME) is required for lipopolysaccharide (LPS) biosynthesis in most genera of pathogenic and non-pathogenic Gram-negative bacteria. It catalyzes the interconversion of ADP-D-glycero-D-mannoheptose and ADP-L-glycero-D-mannoheptose, a precursor of the seven-carbon sugar L-glycero-mannoheptose (heptose). Heptose is an obligatory component of the LPS core domain; its absence results in a truncated LPS structure resulting in susceptibility to hydrophobic antibiotics. Heptose is not found in mammalian cells, thus its biosynthetic pathway in bacteria presents a unique target for the design of novel antimicrobial agents. RESULTS: The structure of AGME, in complex with NADP and the catalytic inhibitor ADP-glucose, has been determined at 2.0 A resolution by multiwavelength anomalous diffraction (MAD) phasing methods. AGME is a homopentameric enzyme, which crystallizes with two pentamers in the asymmetric unit. The location of 70 crystallographically independent selenium sites was a key step in the structure determination process. Each monomer comprises two domains: a large N-terminal domain, consisting of a modified seven-stranded Rossmann fold that is associated with NADP binding; and a smaller alpha/beta C-terminal domain involved in substrate binding. CONCLUSIONS: The first structure of an LPS core biosynthetic enzyme leads to an understanding of the mechanism of the conversion between ADP-D-glycero--mannoheptose and ADP-L-glycero-D-mannoheptose. On the basis of its high structural similarity to UDP-galactose epimerase and the three-dimensional positions of the conserved residues Ser116, Tyr140 and Lys144, AGME was classified as a member of the short-chain dehydrogenase/reductase (SDR) superfamily. This study should prove useful in the design of mechanistic and structure-based inhibitors of the AGME catalyzed reaction. |
==About this Structure== | ==About this Structure== | ||
| - | 1EQ2 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 NAP and ADQ as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/ADP-glyceromanno-heptose_6-epimerase ADP-glyceromanno-heptose 6-epimerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.20 5.1.3.20] Full crystallographic information is available from [http:// | + | 1EQ2 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=NAP:'>NAP</scene> and <scene name='pdbligand=ADQ:'>ADQ</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/ADP-glyceromanno-heptose_6-epimerase ADP-glyceromanno-heptose 6-epimerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.20 5.1.3.20] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EQ2 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Deacon, A | + | [[Category: Deacon, A M.]] |
| - | [[Category: Ealick, S | + | [[Category: Ealick, S E.]] |
| - | [[Category: Jr., W | + | [[Category: Jr., W G.Coleman.]] |
| - | [[Category: Ni, Y | + | [[Category: Ni, Y S.]] |
[[Category: ADQ]] | [[Category: ADQ]] | ||
[[Category: NAP]] | [[Category: NAP]] | ||
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[[Category: short-chain dehydrogenase/reductase fold]] | [[Category: short-chain dehydrogenase/reductase fold]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:30:22 2008'' |
Revision as of 10:30, 21 February 2008
|
THE CRYSTAL STRUCTURE OF ADP-L-GLYCERO-D-MANNOHEPTOSE 6-EPIMERASE
Overview
BACKGROUND: ADP-L-glycero--mannoheptose 6-epimerase (AGME) is required for lipopolysaccharide (LPS) biosynthesis in most genera of pathogenic and non-pathogenic Gram-negative bacteria. It catalyzes the interconversion of ADP-D-glycero-D-mannoheptose and ADP-L-glycero-D-mannoheptose, a precursor of the seven-carbon sugar L-glycero-mannoheptose (heptose). Heptose is an obligatory component of the LPS core domain; its absence results in a truncated LPS structure resulting in susceptibility to hydrophobic antibiotics. Heptose is not found in mammalian cells, thus its biosynthetic pathway in bacteria presents a unique target for the design of novel antimicrobial agents. RESULTS: The structure of AGME, in complex with NADP and the catalytic inhibitor ADP-glucose, has been determined at 2.0 A resolution by multiwavelength anomalous diffraction (MAD) phasing methods. AGME is a homopentameric enzyme, which crystallizes with two pentamers in the asymmetric unit. The location of 70 crystallographically independent selenium sites was a key step in the structure determination process. Each monomer comprises two domains: a large N-terminal domain, consisting of a modified seven-stranded Rossmann fold that is associated with NADP binding; and a smaller alpha/beta C-terminal domain involved in substrate binding. CONCLUSIONS: The first structure of an LPS core biosynthetic enzyme leads to an understanding of the mechanism of the conversion between ADP-D-glycero--mannoheptose and ADP-L-glycero-D-mannoheptose. On the basis of its high structural similarity to UDP-galactose epimerase and the three-dimensional positions of the conserved residues Ser116, Tyr140 and Lys144, AGME was classified as a member of the short-chain dehydrogenase/reductase (SDR) superfamily. This study should prove useful in the design of mechanistic and structure-based inhibitors of the AGME catalyzed reaction.
About this Structure
1EQ2 is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as ADP-glyceromanno-heptose 6-epimerase, with EC number 5.1.3.20 Full crystallographic information is available from OCA.
Reference
The crystal structure of ADP-L-glycero-D-mannoheptose 6-epimerase: catalysis with a twist., Deacon AM, Ni YS, Coleman WG Jr, Ealick SE, Structure. 2000 May 15;8(5):453-62. PMID:10896473
Page seeded by OCA on Thu Feb 21 12:30:22 2008
