title: The MORPHEUS II protein crystallization screen.
abstract: High-quality macromolecular crystals are a prerequisite for the process of protein structure determination by X-ray diffraction. Unfortunately, the relative yield of diffraction-quality crystals from crystallization experiments is often very low. In this context, innovative crystallization screen formulations are continuously being developed. In the past, MORPHEUS, a screen in which each condition integrates a mix of additives selected from the Protein Data Bank, a cryoprotectant and a buffer system, was developed. Here, MORPHEUS II, a follow-up to the original 96-condition initial screen, is described. Reagents were selected to yield crystals when none might be observed in traditional initial screens. Besides, the screen includes heavy atoms for experimental phasing and small polyols to ensure the cryoprotection of crystals. The suitability of the resulting novel conditions is shown by the crystallization of a broad variety of protein samples and their efficiency is compared with commercially available conditions.
authors.affiliation: MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, England.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Gorrec
mesh_terms: D003460:Crystallization / Q000379:methods*; D030562:Databases, Protein / Q000639:trends; D046911:Macromolecular Substances / Q000032:analysis / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D046911:Macromolecular Substances
keywords: MORPHEUS II; crystallization additives; crystallization screening; heavy-atom derivatization; macromolecular crystallography; protein crystallization