PDBsum entry 2opc

Protein binding, metal binding protein

PDB id: 2opc

Contents

Protein chain

115 a.a.

Ligands

IMD

Metals

_CO

Waters ×190

References listed in PDB file

Key reference

Title

The use of co2+ for crystallization and structure determination, Using a conventional monochromatic X-Ray source, Of flax rust avirulence protein.

Authors

G.Guncar, C.I.Wang, J.K.Forwood, T.Teh, A.M.Catanzariti, J.G.Ellis, P.N.Dodds, B.Kobe.

Ref.

Acta Crystallogr Sect F Struct Biol Cryst Commun, 2007, 63, 209-213. [DOI no: 10.1107/S1744309107004599]

PubMed id

17329816

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.

Figure 1.
Representative crystal of Co-AvrL567-A grown in 10% PEG 8000, 0.1 M imidazole pH 8.5 and 17.5 mM CoCl[2]. The blue colour suggested tetrahedral Co^2+ coordination. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 March 1; 63(Pt 3): 209–213. Published online 2007 February 23. doi: 10.1107/S1744309107004599. Copyright [copyright] International Union of Crystallography 2007

Figure 4.
The tetrahedral cobalt coordination-facilitated crystal contacts. The figure shows a stereoview of the SAD electron density (following density modification with DM and RESOLVE) at 2.0 A resolution contoured at 1.0[sigma] (black) and the anomalous map contoured at 5.0[sigma] (magenta); superimposed is the refined model of AvrL567-A shown in stick representation. Cobalt is shown as a green sphere and C atoms from the symmetry-related molecule are shown in green, otherwise they are shown in light blue; N, O and S atoms are shown in dark blue, red and yellow, respectively. The imidazole molecule at the top comes from the crystallization solution. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 March 1; 63(Pt 3): 209–213. Published online 2007 February 23. doi: 10.1107/S1744309107004599. Copyright [copyright] International Union of Crystallography 2007

The above figures are reprinted from an Open Access publication published by the IUCr: Acta Crystallogr Sect F Struct Biol Cryst Commun (2007, 63, 209-213) copyright 2007.