Crystallography Research Today is a free monthly online journal that collates and summarizes the latest research about Crystallography, including details on x-ray crystals, techniques, analyses, structures.

The use of Co2+ for crystallization and structure determination, using a conventional monochromatic X-ray source, of flax rust avirulence protein.

Guncar G, Wang CI, Forwood JK, Teh T, Catanzariti AM, Ellis JG, Dodds PN, Kobe B

School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Qld 4072, Australia.

Metal-binding sites are ubiquitous in proteins and can be readily utilized for phasing. It is shown that a protein crystal structure can be solved using single-wavelength anomalous diffraction based on the anomalous signal of a cobalt ion measured on a conventional monochromatic X-ray source. The unique absorption edge of cobalt (1.61 A) is compatible with the Cu K alpha wavelength (1.54 A) commonly available in macromolecular crystallography laboratories. This approach was applied to the determination of the structure of Melampsora lini avirulence protein AvrL567-A, a protein with a novel fold from the fungal pathogen flax rust that induces plant disease resistance in flax plants. This approach using cobalt ions may be applicable to all cobalt-binding proteins and may be advantageous when synchrotron radiation is not readily available.

Published 1 March 2007 in Acta Crystallograph Sect F Struct Biol Cryst Commun, 63: 209-13.
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