Connectivity-based ab initio phasing: from low resolution to a secondary structure.

Natalia Lunina; Vladimir Y Lunin; Alexandre Urzhumtsev

doi:10.1107/s0907444903015154

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Connectivity-based ab initio phasing: from low resolution to a secondary structure.

Natalia Lunina·Vladimir Y Lunin·Alexandre Urzhumtsev

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Abstract

The connectivity-based phasing method currently allows ab initio determination of phases for several hundred reflections. In the case of large macromolecular crystals, these reflections correspond to a very low resolution and the structural information deduced essentially consists of the molecular packing and an approximate molecular envelope. However, when the unit cell is relatively small, such a phasing procedure can produce phases such that secondary-structure elements can be identified in the corresponding maps. In the case of the pheromone Er-1, all three alpha-helices present are seen in the ab initio phased maps. In the case of protein G, not only the alpha-helix but also some individual beta-strands are distinguishable.

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Cluster Analysis Crystallization Crystallography, X-Ray Fourier Analysis GTP-Binding Proteins Models, Chemical Models, Molecular Pheromones Protein Structure, Secondary Proteins Comparative Study Journal Article Research Support, Non-U.S. Gov't

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Natalia Lunina, Vladimir Y Lunin, Alexandre Urzhumtsev. 2003-09-19. Connectivity-based ab initio phasing: from low resolution to a secondary structure.. https://doi.org/10.1107/s0907444903015154

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