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==Overview== | ==Overview== | ||
The crystal structure of the tyrosine-bound T state of allosteric yeast, Saccharomyces cerevisiae chorismate mutase was solved by molecular, replacement at a resolution of 2.8 angstroms using a monomer of the, R-state structure as the search model. The allosteric inhibitor tyrosine, was found to bind in the T state at the same binding site as the, allosteric activator tryptophan binds in the R state, thus defining one, regulatory binding site for each monomer. Activation by tryptophan is, caused by the larger steric size of its side chain, thereby pushing apart, the allosteric domain of one monomer and helix H8 of the catalytic domain, of the other monomer. Inhibition is caused by polar contacts of tyrosine, with Arg-75 and Arg-76 of one monomer and with Gly-141, Ser-142, and, Thr-145 of ... | The crystal structure of the tyrosine-bound T state of allosteric yeast, Saccharomyces cerevisiae chorismate mutase was solved by molecular, replacement at a resolution of 2.8 angstroms using a monomer of the, R-state structure as the search model. The allosteric inhibitor tyrosine, was found to bind in the T state at the same binding site as the, allosteric activator tryptophan binds in the R state, thus defining one, regulatory binding site for each monomer. Activation by tryptophan is, caused by the larger steric size of its side chain, thereby pushing apart, the allosteric domain of one monomer and helix H8 of the catalytic domain, of the other monomer. Inhibition is caused by polar contacts of tyrosine, with Arg-75 and Arg-76 of one monomer and with Gly-141, Ser-142, and, Thr-145 of the other monomer, thereby bringing the allosteric and, catalytic domains closer together. The allosteric transition includes an 8, degree rotation of each of the two catalytic domains relative to the, allosteric domains of each monomer (domain closure). Alternatively, this, transition can be described as a 15 degree rotation of the catalytic, domains of the dimer relative to each other. | ||
==About this Structure== | ==About this Structure== | ||
2CSM is a | 2CSM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with TYR as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Chorismate_mutase Chorismate mutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.4.99.5 5.4.99.5] Structure known Active Sites: CAT and REG. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2CSM OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: complex (isomerase/peptide)]] | [[Category: complex (isomerase/peptide)]] | ||
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Revision as of 15:57, 5 November 2007
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TYR-BOUND T-STATE OF YEAST CHORISMATE MUTASE
OverviewOverview
The crystal structure of the tyrosine-bound T state of allosteric yeast, Saccharomyces cerevisiae chorismate mutase was solved by molecular, replacement at a resolution of 2.8 angstroms using a monomer of the, R-state structure as the search model. The allosteric inhibitor tyrosine, was found to bind in the T state at the same binding site as the, allosteric activator tryptophan binds in the R state, thus defining one, regulatory binding site for each monomer. Activation by tryptophan is, caused by the larger steric size of its side chain, thereby pushing apart, the allosteric domain of one monomer and helix H8 of the catalytic domain, of the other monomer. Inhibition is caused by polar contacts of tyrosine, with Arg-75 and Arg-76 of one monomer and with Gly-141, Ser-142, and, Thr-145 of the other monomer, thereby bringing the allosteric and, catalytic domains closer together. The allosteric transition includes an 8, degree rotation of each of the two catalytic domains relative to the, allosteric domains of each monomer (domain closure). Alternatively, this, transition can be described as a 15 degree rotation of the catalytic, domains of the dimer relative to each other.
About this StructureAbout this Structure
2CSM is a Single protein structure of sequence from Saccharomyces cerevisiae with TYR as ligand. Active as Chorismate mutase, with EC number 5.4.99.5 Structure known Active Sites: CAT and REG. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the T state of allosteric yeast chorismate mutase and comparison with the R state., Strater N, Hakansson K, Schnappauf G, Braus G, Lipscomb WN, Proc Natl Acad Sci U S A. 1996 Apr 16;93(8):3330-4. PMID:8622937
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