1qdl: Difference between revisions
New page: left|200px<br /><applet load="1qdl" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qdl, resolution 2.500Å" /> '''THE CRYSTAL STRUCTU... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1qdl.jpg|left|200px]]<br /><applet load="1qdl" size=" | [[Image:1qdl.jpg|left|200px]]<br /><applet load="1qdl" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1qdl, resolution 2.500Å" /> | caption="1qdl, resolution 2.500Å" /> | ||
'''THE CRYSTAL STRUCTURE OF ANTHRANILATE SYNTHASE FROM SULFOLOBUS SOLFATARICUS'''<br /> | '''THE CRYSTAL STRUCTURE OF ANTHRANILATE SYNTHASE FROM SULFOLOBUS SOLFATARICUS'''<br /> | ||
==Overview== | ==Overview== | ||
Anthranilate synthase catalyzes the synthesis of anthranilate from | Anthranilate synthase catalyzes the synthesis of anthranilate from chorismate and glutamine and is feedback-inhibited by tryptophan. The enzyme of the hyperthermophile Sulfolobus solfataricus has been crystallized in the absence of physiological ligands, and its three-dimensional structure has been determined at 2.5-A resolution with x-ray crystallography. It is a heterotetramer of anthranilate synthase (TrpE) and glutamine amidotransferase (TrpG) subunits, in which two TrpG:TrpE protomers associate mainly via the TrpG subunits. The small TrpG subunit (195 residues) has the known "triad" glutamine amidotransferase fold. The large TrpE subunit (421 residues) has a novel fold. It displays a cleft between two domains, the tips of which contact the TrpG subunit across its active site. Clusters of catalytically essential residues are located inside the cleft, spatially separated from clustered residues involved in feedback inhibition. The structure suggests a model in which chorismate binding triggers a relative movement of the two domain tips of the TrpE subunit, activating the TrpG subunit and creating a channel for passage of ammonia toward the active site of the TrpE subunit. Tryptophan presumably blocks this rearrangement, thus stabilizing the inactive states of both subunits. The structure of the TrpE subunit is a likely prototype for the related enzymes 4-amino 4-deoxychorismate synthase and isochorismate synthase. | ||
==About this Structure== | ==About this Structure== | ||
1QDL is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus]. 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:// | 1QDL is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus]. 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=1QDL OCA]. | ||
==Reference== | ==Reference== | ||
| Line 18: | Line 18: | ||
[[Category: Hester, G.]] | [[Category: Hester, G.]] | ||
[[Category: Ivens, A.]] | [[Category: Ivens, A.]] | ||
[[Category: Jansonius, J | [[Category: Jansonius, J N.]] | ||
[[Category: Kirschner, K.]] | [[Category: Kirschner, K.]] | ||
[[Category: Knoechel, T.]] | [[Category: Knoechel, T.]] | ||
| Line 27: | Line 27: | ||
[[Category: tryptophan biosynthesis]] | [[Category: tryptophan biosynthesis]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:38:32 2008'' | ||
Revision as of 15:38, 21 February 2008
|
THE CRYSTAL STRUCTURE OF ANTHRANILATE SYNTHASE FROM SULFOLOBUS SOLFATARICUS
OverviewOverview
Anthranilate synthase catalyzes the synthesis of anthranilate from chorismate and glutamine and is feedback-inhibited by tryptophan. The enzyme of the hyperthermophile Sulfolobus solfataricus has been crystallized in the absence of physiological ligands, and its three-dimensional structure has been determined at 2.5-A resolution with x-ray crystallography. It is a heterotetramer of anthranilate synthase (TrpE) and glutamine amidotransferase (TrpG) subunits, in which two TrpG:TrpE protomers associate mainly via the TrpG subunits. The small TrpG subunit (195 residues) has the known "triad" glutamine amidotransferase fold. The large TrpE subunit (421 residues) has a novel fold. It displays a cleft between two domains, the tips of which contact the TrpG subunit across its active site. Clusters of catalytically essential residues are located inside the cleft, spatially separated from clustered residues involved in feedback inhibition. The structure suggests a model in which chorismate binding triggers a relative movement of the two domain tips of the TrpE subunit, activating the TrpG subunit and creating a channel for passage of ammonia toward the active site of the TrpE subunit. Tryptophan presumably blocks this rearrangement, thus stabilizing the inactive states of both subunits. The structure of the TrpE subunit is a likely prototype for the related enzymes 4-amino 4-deoxychorismate synthase and isochorismate synthase.
About this StructureAbout this Structure
1QDL is a Protein complex structure of sequences from Sulfolobus solfataricus. Active as Anthranilate synthase, with EC number 4.1.3.27 Full crystallographic information is available from OCA.
ReferenceReference
The crystal structure of anthranilate synthase from Sulfolobus solfataricus: functional implications., Knochel T, Ivens A, Hester G, Gonzalez A, Bauerle R, Wilmanns M, Kirschner K, Jansonius JN, Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9479-84. PMID:10449718
Page seeded by OCA on Thu Feb 21 14:38:32 2008