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Publication Abstract from PubMed

The growth of diffraction-quality crystals and experimental phasing remain two of the main bottlenecks in protein crystallography. Here, the high-affinity copper(II)-binding tripeptide GHK was fused to the N-terminus of a GFP variant and an MBP-FG peptide fusion. The GHK tag promoted crystallization, with various residues (His, Asp, His/Pro) from symmetry molecules completing the copper(II) square-pyramidal coordination sphere. Rapid structure determination by copper SAD phasing could be achieved, even at a very low Bijvoet ratio or after significant radiation damage. When collecting highly redundant data at a wavelength close to the copper absorption edge, residual S-atom positions could also be located in log-likelihood-gradient maps and used to improve the phases. The GHK copper SAD method provides a convenient way of both crystallizing and phasing macromolecular structures, and will complement the current trend towards native sulfur SAD and MR-SAD phasing.

The copper(II)-binding tripeptide GHK, a valuable crystallization and phasing tag for macromolecular crystallography.,Mehr A, Henneberg F, Chari A, Gorlich D, Huyton T Acta Crystallogr D Struct Biol. 2020 Dec 1;76(Pt 12):1222-1232. doi:, 10.1107/S2059798320013741. Epub 2020 Nov 19. PMID:33263328^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.