1GWG

Tri-iodide derivative of apoferritin

Summary for 1GWG

• Entry DOI: 10.2210/pdb1gwg/pdb
• Related: 1AEW 1DAT 1HRS 1IER 1IES
• Descriptor: FERRITIN LIGHT CHAIN, IODIDE ION, CADMIUM ION, ... (4 entities in total)
• Functional Keywords: ferritin, iron storage, multigene family, acetylation
• Biological source: EQUUS CABALLUS (HORSE)
• Total number of polymer chains: 1
• Total formula weight: 21239.39

Authors

Evans, G.,Bricogne, G. (deposition date: 2002-03-15, release date: 2002-06-06, Last modification date: 2024-05-08)

Primary citation

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.,Sect.D, 58:976-, 2002

PubMed Abstract: 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.

PubMed: 12037300
DOI: 10.1107/S0907444902005486

Experimental method

X-RAY DIFFRACTION (2.01 Å)