1k7e: Difference between revisions
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|PDB= 1k7e |SIZE=350|CAPTION= <scene name='initialview01'>1k7e</scene>, resolution 2.30Å | |PDB= 1k7e |SIZE=350|CAPTION= <scene name='initialview01'>1k7e</scene>, resolution 2.30Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=IAG:N-[1H-INDOL-3-YL-ACETYL]GLYCINE+ACID'>IAG</scene> and <scene name='pdbligand=PLP:PYRIDOXAL-5 | |LIGAND= <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=IAG:N-[1H-INDOL-3-YL-ACETYL]GLYCINE+ACID'>IAG</scene> and <scene name='pdbligand=PLP:PYRIDOXAL-5'-PHOSPHATE'>PLP</scene> | ||
|ACTIVITY= [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] | |ACTIVITY= [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] | ||
|GENE= TRPA/TRPB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=602 Salmonella typhimurium]) | |GENE= TRPA/TRPB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=602 Salmonella typhimurium]) | ||
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[[Category: tryptophan biosynthesis]] | [[Category: tryptophan biosynthesis]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 23 12:26:54 2008'' | ||
Revision as of 13:26, 23 March 2008
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| , resolution 2.30Å | |||||||
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| Ligands: | , and | ||||||
| Gene: | TRPA/TRPB (Salmonella typhimurium) | ||||||
| Activity: | Tryptophan synthase, with EC number 4.2.1.20 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF WILD-TYPE TRYPTOPHAN SYNTHASE COMPLEXED WITH N-[1H-INDOL-3-YL-ACETYL]GLYCINE ACID
OverviewOverview
Tryptophan synthase is a bifunctional alpha(2)beta(2) complex catalyzing the last two steps of l-tryptophan biosynthesis. The natural substrates of the alpha-subunit indole- 3-glycerolphosphate and glyceraldehyde-3-phosphate, and the substrate analogs indole-3-propanolphosphate and dl-alpha-glycerol-3-phosphate are allosteric effectors of the beta-subunit activity. It has been shown recently, that the indole-3-acetyl amino acids indole-3-acetylglycine and indole-3-acetyl-l-aspartic acid are both alpha-subunit inhibitors and beta-subunit allosteric effectors, whereas indole-3-acetyl-l-valine is only an alpha-subunit inhibitor (Marabotti, A., Cozzini, P., and Mozzarelli, A. (2000) Biochim. Biophys. Acta 1476, 287-299). The crystal structures of tryptophan synthase complexed with indole-3-acetylglycine and indole-3-acetyl-l-aspartic acid show that both ligands bind to the active site such that the carboxylate moiety is positioned similarly as the phosphate group of the natural substrates. As a consequence, the residues of the alpha-active site that interact with the ligands are the same as observed in the indole 3-glycerolphosphate-enzyme complex. Ligand binding leads to closure of loop alphaL6 of the alpha-subunit, a key structural element of intersubunit communication. This is in keeping with the allosteric role played by these compounds. The structure of the enzyme complex with indole-3-acetyl-l-valine is quite different. Due to the hydrophobic lateral chain, this molecule adopts a new orientation in the alpha-active site. In this case, closure of loop alphaL6 is no longer observed, in agreement with its functioning only as an inhibitor of the alpha-subunit reaction.
About this StructureAbout this Structure
1K7E is a Protein complex structure of sequences from Salmonella typhimurium. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of a new class of allosteric effectors complexed to tryptophan synthase., Weyand M, Schlichting I, Marabotti A, Mozzarelli A, J Biol Chem. 2002 Mar 22;277(12):10647-52. Epub 2001 Dec 26. PMID:11756456
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