@article{gledocs_11858_8452, author = {Mehr, Alexander and Henneberg, Fabian and Chari, Ashwin and Görlich, Dirk and Huyton, Trevor}, title = {The copper(II)‐binding tripeptide GHK, a valuable crystallization and phasing tag for macromolecular crystallography}, year = {2020-12-02}, volume = {76}, number = {12}, pages = {1222-1232}, publisher = {International Union of Crystallography}, publisher = {5 Abbey Square, Chester, Cheshire CH1 2HU, England}, abstract = {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.}, note = { \url {http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8452}}, }