1gw9: Difference between revisions

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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 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.
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==
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[[Category: xylose metabolism]]
[[Category: xylose metabolism]]


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