title: The use of Co2+ for crystallization and structure determination, using a conventional monochromatic X-ray source, of flax rust avirulence protein.
abstract: 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.
authors.affiliation: School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Qld 4072, Australia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Guncar
authors.forename: Ching-I A
authors.initials: CI
authors.lastname: Wang
authors.forename: Jade K
authors.initials: JK
authors.lastname: Forwood
authors.forename: Trazel
authors.initials: T
authors.lastname: Teh
authors.forename: Ann-Maree
authors.initials: AM
authors.lastname: Catanzariti
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ellis
authors.forename: Peter N
authors.initials: PN
authors.lastname: Dodds
authors.forename: Bostjan
authors.initials: B
authors.lastname: Kobe
mesh_terms: D001487:Basidiomycota / Q000737:chemistry* / Q000472:pathogenicity; D003035:Cobalt / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D019597:Flax / Q000737:chemistry / Q000382:microbiology*; D005656:Fungal Proteins / Q000737:chemistry*; D010935:Plant Diseases / Q000382:microbiology; D014774:Virulence / Q000502:physiology
chemical_list: D005656:Fungal Proteins; D003035:Cobalt