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1gw9
From Proteopedia
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==Overview== | ==Overview== | ||
| - | A series of experiments performed at Cu Kalpha wavelength on in-house, X-ray equipment are presented which investigate two possibilities for, enhancing the experimental phasing signal by means of (i) triiodide/iodide, soaks using KI/I(2) and (ii) combinations of counter-ions introduced using, the short cryosoak method. Triiodide-derivative crystal structures for, five test proteins have been refined and reveal that iodine can bind as, polyiodide and single iodide ions through hydrophobic and hydrogen-bonding, interactions both at the molecular surface and in intramolecular and, intermolecular cavities. In three cases, the structures could be, automatically determined with autoSHARP using in-house SAD and SIRAS data., The investigation of combinatorial counter-ion replacement using | + | A series of experiments performed at Cu Kalpha wavelength on in-house, X-ray equipment are presented which investigate two possibilities for, enhancing the experimental phasing signal by means of (i) triiodide/iodide, soaks using KI/I(2) and (ii) combinations of counter-ions introduced using, the short cryosoak method. Triiodide-derivative crystal structures for, five test proteins have been refined and reveal that iodine can bind as, polyiodide and single iodide ions through hydrophobic and hydrogen-bonding, interactions both at the molecular surface and in intramolecular and, intermolecular cavities. In three cases, the structures could be, automatically determined with autoSHARP using in-house SAD and SIRAS data., The investigation of combinatorial counter-ion replacement using multiple, salts with Na(+) and Cs(+) as cations and I(-) and Cl(-) as anions reveals, that, for the case of hen egg-white lysozyme, significant improvement in, phasing signal is obtained by the combined use of salts compared with, SIRAS methods using native and single short-soak derivative data sets. |
==About this Structure== | ==About this Structure== | ||
| - | 1GW9 is a | + | 1GW9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_rubiginosus Streptomyces rubiginosus] with LXC, CA and IOD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Xylose_isomerase Xylose isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.5 5.3.1.5] Structure known Active Site: CA1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1GW9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: xylose metabolism]] | [[Category: xylose metabolism]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:36:14 2007'' |
Revision as of 10:30, 5 November 2007
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TRI-IODIDE DERIVATIVE OF XYLOSE ISOMERASE FROM STREPTOMYCES RUBIGINOSUS
Overview
A series of experiments performed at Cu Kalpha wavelength on in-house, X-ray equipment are presented which investigate two possibilities for, enhancing the experimental phasing signal by means of (i) triiodide/iodide, soaks using KI/I(2) and (ii) combinations of counter-ions introduced using, the short cryosoak method. Triiodide-derivative crystal structures for, five test proteins have been refined and reveal that iodine can bind as, polyiodide and single iodide ions through hydrophobic and hydrogen-bonding, interactions both at the molecular surface and in intramolecular and, intermolecular cavities. In three cases, the structures could be, automatically determined with autoSHARP using in-house SAD and SIRAS data., The investigation of combinatorial counter-ion replacement using multiple, salts with Na(+) and Cs(+) as cations and I(-) and Cl(-) as anions reveals, that, for the case of hen egg-white lysozyme, significant improvement in, phasing signal is obtained by the combined use of salts compared with, SIRAS methods using native and single short-soak derivative data sets.
About this Structure
1GW9 is a Single protein structure of sequence from Streptomyces rubiginosus with LXC, CA and IOD as ligands. Active as Xylose isomerase, with EC number 5.3.1.5 Structure known Active Site: CA1. Full crystallographic information is available from OCA.
Reference
Triiodide derivatization and combinatorial counter-ion replacement: two methods for enhancing phasing signal using laboratory Cu Kalpha X-ray equipment., Evans G, Bricogne G, Acta Crystallogr D Biol Crystallogr. 2002 Jun;58(Pt 6 Pt 2):976-91. Epub, 2002 May 29. PMID:12037300
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