SPring-8, the large synchrotron radiation facility

Speaker : Thomas R. Schneider

Language : ENGLISH

Affiliation : EMBL@PETRA3, Germany

Title : EMBL at PETRA III. New beam lines and phasing tools.

Abstract :
EMBL Hamburg has constructed three beamlines for structural biology applications at the high-brilliance/low-emmittance synchrotron radiation source PETRA III at DESY (Hamburg, Germany). Two beamlines (P13, P14) provide excellent condition for diffraction data collection on macromolecular crystals (MX); one beamline (P12) offers highly sensitive and automated small-angle X-ray scattering experiments on solutions of biological macromolecules (SAXS). User operation has commenced in 2012.
P12 provides cutting-edge conditions for SAXS-experiments with a photon flux of >10¹³ ph/sec into a 200 x 100 μm² focus with a practically negligible beam divergence (< 40 x 10 μrad²). The beamline features an automated BioSAXS sample changer, a variable-length detector tube and a PILATUS 2M detector for fast acquisition of high-quality data. An on-line FLPC system coupled with a Malvern triple detector array measuring UV absorption, light scattering and refractive index is available for routine user operation. The beamline software and automated analysis pipeline ensure automated data collection and on-the-fly analysis. The experiments can be run remotely via an NX Client desktop (NoMachine S.á r.l).
P13 offers a photon flux of >10¹³ ph/sec from 16 keV down to 6 keV. Energies between 4 and 6 keV are accessible with a photon flux between 10¹² and 10¹³ ph/sec providing unique conditions for experimental phasing. Employing adaptive focusing mirrors, the full beam (ca 1.5 x 1 mm²) can be focused to a size of ca. 30 x 20 μm² resulting in a crystal lifetime on the order of 10 sec. An MD2 diffractometer with a kappa goniostat allows for rapid and accurate rotation of crystals in the X-ray beam. Diffraction data are collected in shutter-less mode on a PILATUS 6M detector with a 25 Hz readout-frequency. Data can be processed on the fly using an 80-core dedicated computer system.
P14 offers a photon flux of > 10¹³ ph/sec between 7 and 35 keV. Using adaptive focusing mirrors, a beamsize of 7 x 5 μm² with a total flux of >10¹² ph/sec can be used for crystallographic experiments. In this beam, the crystal lifetime is less than 1 sec. Based on highly accurate mechanics the focusing mirrors can be reproducibly moved into and out of the beam in less than half a minute allowing to quickly toggle between fully focused small beam and unfocused large (1.5 x 1 mm²) beam to optimize data collection parameters for differently sized crystals. A high-precision vertically mounted MD3 diffractometer with a sphere of confusion of less than 100 nm (with mini-kappa goniostat mounted) is available for data collection. Detector and data processing infrastructure are identical to P13.
The beamlines are embedded into the ‘Integrated Facility for Structural Biology’ offering upstream facilities for sample preparation and characterization and a laboratory specifically equipped for the preparation of heavy atom derivatives of macromolecular crystals and downstream facilities for the evaluation of the collected diffraction/scattering data in terms of crystallographic or SAXS-models.
I will report about the status of the beamlines, the updated version of the phasing tool ‘HKL2MAP’, describe typical experimental situations, and present some results.

Organizer：Kazuya Hasegawa
Mail : kazuya@spring8.or.jp
PHS : 3595