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The Crystal Screening Interface at ALS
Crystallography Beam Line Automation: Work Smarter Not Harder Stanford Synchrotron Radiation Laboratory—30th Annual Users’ Meeting October 8, 2003 The Crystal Screening Interface at ALS Nicholas Sauter, Lawrence Berkeley National Lab Paul Adams, Computational Crystallography Initiative Thomas Earnest, Berkeley Center for Structural Biology
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Robohutch: Sector 5 Beamlines
Magnetic pins 112 Samples Tools Auto-centering Shipping dewar Robohutch Magnetic pins 112 Samples Tools Auto-centering Shipping dewar Robohutch
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Initial Data Entry
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The Screening Interface
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How many images should I collect?
Symmetry results based on… One Image Two images 90° apart True Beam Center Orthorhombic (correct) Conventional Autoindexing Monoclinic (not quite correct) 0.5 mm Wrong Indexing Beam Center Predetermination No Indexing
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Fix Misindexing With LABELIT
Common experience: the predicted pattern looks almost right, but something is “funny” Systematic absence of h + k odd Easily detected and corrected, once the problem is recognized
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Data Processing Sequence
Final Score Success Resolution cutoff Mosaic spread RMS residual Good strategy Few overlaps No ice rings Well-shaped spots Minimal diffuse scatter Short exposure time Collect 2 oscillation frames 90° apart Autoindex Determine Bravais lattice LABELIT 15 seconds Characterize the diffraction pattern DISTL (Ashley Deacon, SSRL) 5 seconds Integrate MOSFLM 20 seconds Heuristic score within each group: score = 1 – (.7*e– 4/resolution) – (1.5*rmsResidual) – (.02*mosaicity) Representative results: protein Syrrx-004
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Software Goals Provide automation by linking separate modules
Data Repository Screening Crystal Selection Data Collection Reduction Analysis Provide automation by linking separate modules Genomics Project Individual Lab Anticipate scenarios where modules work together Single- Wavelength Anomalous Dispersion Screen All Crystals Score Strategy Inverse Beam Collection Cumu- lative Each Image Fluorescence Scan Eliminate Sample Heavy-Atom Search Signal Refinement
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Acknowledgements Computational Crystallography Initiative (LBNL)
Paul Adams Ralf Grosse-Kunstleve Nigel Moriarty Berkeley Center for Structural Biology (LBNL) Thomas Earnest Robert Nordmeyer Carl Cork Earl Cornell John Taylor Stanford Synchrotron Radiation Laboratory Ashley Deacon Zepu Zhang Syrrx, Inc. Gyorgy Snell MRC Laboratory of Molecular Biology Andrew Leslie Harry Powell Daresbury Laboratory Martyn Winn
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