1i7q
From Proteopedia
(New page: 200px<br /><applet load="1i7q" size="450" color="white" frame="true" align="right" spinBox="true" caption="1i7q, resolution 1.95Å" /> '''ANTHRANILATE SYNTHAS...) |
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| - | [[Image:1i7q.jpg|left|200px]]<br /><applet load="1i7q" size=" | + | [[Image:1i7q.jpg|left|200px]]<br /><applet load="1i7q" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1i7q, resolution 1.95Å" /> | caption="1i7q, resolution 1.95Å" /> | ||
'''ANTHRANILATE SYNTHASE FROM S. MARCESCENS'''<br /> | '''ANTHRANILATE SYNTHASE FROM S. MARCESCENS'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of anthranilate synthase (AS) from Serratia | + | The crystal structure of anthranilate synthase (AS) from Serratia marcescens, a mesophilic bacterium, has been solved in the presence of its substrates, chorismate and glutamine, and one product, glutamate, at 1.95 A, and with its bound feedback inhibitor, tryptophan, at 2.4 A. In comparison with the AS structure from the hyperthermophile Sulfolobus solfataricus, the S. marcescens structure shows similar subunit structures but a markedly different oligomeric organization. One crystal form of the S. marcescens enzyme displays a bound pyruvate as well as a putative anthranilate (the nitrogen group is ambiguous) in the TrpE subunit. It also confirms the presence of a covalently bound glutamyl thioester intermediate in the TrpG subunit. The tryptophan-bound form reveals that the inhibitor binds at a site distinct from that of the substrate, chorismate. Bound tryptophan appears to prevent chorismate binding by a demonstrable conformational effect, and the structure reveals how occupancy of only one of the two feedback inhibition sites can immobilize the catalytic activity of both TrpE subunits. The presence of effectors in the structure provides a view of the locations of some of the amino acid residues in the active sites. Our findings are discussed in terms of the previously described AS structure of S. solfataricus, mutational data obtained from enteric bacteria, and the enzyme's mechanism of action. |
==About this Structure== | ==About this Structure== | ||
| - | 1I7Q is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Serratia_marcescens Serratia marcescens] with MG, ILG, BEZ and PYR as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Anthranilate_synthase Anthranilate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.3.27 4.1.3.27] Full crystallographic information is available from [http:// | + | 1I7Q is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Serratia_marcescens Serratia marcescens] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=ILG:'>ILG</scene>, <scene name='pdbligand=BEZ:'>BEZ</scene> and <scene name='pdbligand=PYR:'>PYR</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Anthranilate_synthase Anthranilate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.3.27 4.1.3.27] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I7Q OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Serratia marcescens]] | [[Category: Serratia marcescens]] | ||
[[Category: Kim, C.]] | [[Category: Kim, C.]] | ||
| - | [[Category: Mills, S | + | [[Category: Mills, S E.]] |
[[Category: Nguyen-Huu, X.]] | [[Category: Nguyen-Huu, X.]] | ||
[[Category: Spraggon, G.]] | [[Category: Spraggon, G.]] | ||
[[Category: Yanofsky, C.]] | [[Category: Yanofsky, C.]] | ||
| - | [[Category: Yee, M | + | [[Category: Yee, M C.]] |
[[Category: BEZ]] | [[Category: BEZ]] | ||
[[Category: ILG]] | [[Category: ILG]] | ||
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[[Category: glutamyl thioester]] | [[Category: glutamyl thioester]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:08:55 2008'' |
Revision as of 11:08, 21 February 2008
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ANTHRANILATE SYNTHASE FROM S. MARCESCENS
Overview
The crystal structure of anthranilate synthase (AS) from Serratia marcescens, a mesophilic bacterium, has been solved in the presence of its substrates, chorismate and glutamine, and one product, glutamate, at 1.95 A, and with its bound feedback inhibitor, tryptophan, at 2.4 A. In comparison with the AS structure from the hyperthermophile Sulfolobus solfataricus, the S. marcescens structure shows similar subunit structures but a markedly different oligomeric organization. One crystal form of the S. marcescens enzyme displays a bound pyruvate as well as a putative anthranilate (the nitrogen group is ambiguous) in the TrpE subunit. It also confirms the presence of a covalently bound glutamyl thioester intermediate in the TrpG subunit. The tryptophan-bound form reveals that the inhibitor binds at a site distinct from that of the substrate, chorismate. Bound tryptophan appears to prevent chorismate binding by a demonstrable conformational effect, and the structure reveals how occupancy of only one of the two feedback inhibition sites can immobilize the catalytic activity of both TrpE subunits. The presence of effectors in the structure provides a view of the locations of some of the amino acid residues in the active sites. Our findings are discussed in terms of the previously described AS structure of S. solfataricus, mutational data obtained from enteric bacteria, and the enzyme's mechanism of action.
About this Structure
1I7Q is a Protein complex structure of sequences from Serratia marcescens with , , and as ligands. Active as Anthranilate synthase, with EC number 4.1.3.27 Full crystallographic information is available from OCA.
Reference
The structures of anthranilate synthase of Serratia marcescens crystallized in the presence of (i) its substrates, chorismate and glutamine, and a product, glutamate, and (ii) its end-product inhibitor, L-tryptophan., Spraggon G, Kim C, Nguyen-Huu X, Yee MC, Yanofsky C, Mills SE, Proc Natl Acad Sci U S A. 2001 May 22;98(11):6021-6. PMID:11371633
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