EMBL Hamburg News
First data collections on EMBL@PETRA3 beamline MX1
Diffraction image recorded on a 100x100x60 µm3 crystal of Zn-free insulin. The pattern was recorded by a Rayonix225HE detector with a 100 mm sample to detector distance using X-ray with an energy of 4.6 keV. The inset shows the experimentally phased electron density at 3.1 Å resolution with a SHELXE-auto-traced model of the protein.
EMBL Hamburg scientists and engineers working on the construction of the new EMBL MX1 beamline at the PETRA III storage ring have experienced a number of highlights over the last few weeks.
The MX1 beamline is one of three EMBL beamlines currently being constructed and commissioned at the PETRA III storage ring on the DESY campus, and has been designed to be a wide energy tunable beamline for macromolecular crystallography. During the last few weeks, development went from having the first beam into the experimental hutch in late November, to full collection of data sets at different energies from 12.6keV to 4.6keV on insulin test crystals by the middle of December.
On the 24th of November the experimental hutch passed the radiation protection tests, and during the following week the MD2 diffractometer, slit box and the detector were installed and commissioned. On the 12th of December the first diffraction image was recorded and two days later the first complete data set was collected. Subsequently, thousands of diffraction images were collected just before the winter shut down. The data appeared immediately to be of excellent quality, preserving even very weak anomalous signals, which in all cases delivered good phasing.
“I am particularly surprised by the quality of the data collected at 4.6keV,” explains Michele Cianci, EMBL staff scientist leading the work on MX1, “normally such data collection requires a dedicated set-up to avoid absorption problems and to produce good data. At MX1, probably because of the very collimated beam, we are already doing really well, and we have margins for improvement. I am very grateful to the entire PETRA III team who have worked really hard to achieve this milestone.”
The next step will be to integrate the focussing mirrors into the beamline optics to reduce the beam size, so that high quality data can be collected from small crystals.