|1gw9, resolution 1.55Å ()|
|Related:||1xib, 1xic, 1xid, 1xie, 1xif, 1xig, 1xih, 1xii, 1xij, 1xis, 2xis, 3xis, 4xis, 8xia, 9xia|
TRI-IODIDE DERIVATIVE OF XYLOSE ISOMERASE FROM STREPTOMYCES RUBIGINOSUS
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.
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
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
- Evans G, Bricogne G. Triiodide derivatization and combinatorial counter-ion replacement: two methods for enhancing phasing signal using laboratory Cu Kalpha X-ray equipment. Acta Crystallogr D Biol Crystallogr. 2002 Jun;58(Pt 6 Pt 2):976-91. Epub, 2002 May 29. PMID:12037300