BL-11C Micro-MX: a high-flux microfocus macromolecular-crystallography beamline for micrometre-sized protein crystals at Pohang Light Source II

Abstract

BL-11C, a new protein crystallography beamline, is an in-vacuum undulator-based microfocus beamline used for macromolecular crystallography at the Pohang Accelerator Laboratory and it was made available to users in June 2017. The beamline is energy tunable in the range 5.0–20 keV to support conventional single- and multi-wavelength anomalous-dispersion experiments against a wide range of heavy metals. At the standard working energy of 12.659 keV, the monochromated beam is focused to 4.1 µm (V) × 8.5 µm (H) full width at half-maximum at the sample position and the measured photon flux is 1.3 × 1012 photons s−1. The experimental station is equipped with a Pilatus3 6M detector, a micro-diffractometer (MD2S) incorporating a multi-axis goniometer, and a robotic sample exchanger (CATS) with a dewar capacity of 90 samples. This beamline is suitable for structural determination of weakly diffracting crystalline substances, such as biomaterials, including protein, nucleic acids and their complexes. In addition, serial crystallography experiments for determining crystal structures at room temperature are possible. Herein, the current beamline characteristics, technical information for users and some recent scientific highlights are described.

pH-Induced structural changes in xylanase GH11 from Thermoanaerobacterium saccharolyticum

“…The X-ray diffraction data were collected on beamline 11C at Pohang Light Source II (PLS-II, Pohang, Republic of Korea). 17 The TsaGH11 crystal was immersed in a cryoprotectant solution consisting of a reservoir solution supplemented with 20% (v/v) glycerol for 10 s. The TsaGH11 crystal was mounted on the goniometer under a liquid nitrogen stream at 100 K. Diffraction data were recorded using a Pilatus 6M detector. Diffraction images were indexed, integrated, and scaled using the HKL2000 program.…”

Robotic Pendant Drop: Containerless Liquid for μs-resolved, AI-executable XPCS

“…Autonomous material discovery combining AI and automated experimental protocols have proven to be an effective method in navigating large parameter space and optimizing material design 17,18 . However, despite the well-developed automation at macromolecular crystallography beamlines [19][20][21][22][23][24][25] , the level of hardware automation at XPCS beamlines is quite limited, primarily because the throughput of XPCS measurements has been traditionally limited by the amount of coherent x-ray flux. This limitation is now being lifted by the world-wide construction/commissioning of Diffraction Limited Storage Rings and Free Electron Lasers around the world, which increases the coherent flux by at least 10 2 and the measurement throughput by 10 4 , reducing sample turnaround time from as long as 15 hours 26 to less than 5 seconds.…”

Structural and bioinformatics analysis of single-domain substrate-binding protein from Rhodothermus marinus

“…X-ray diffraction data were collected on the 11C beamline at Pohang Accelerator Laboratory (Pohang, Republic of Korea) [ 15 ]. For metal soaking, the RmSBP crystals obtained in Index D8 and G11 conditions were immersed in a reservoir solution containing 0.1 mM NaBr or HgCl 2 for 30 s, respectively, and then cryoprotected using a cryoprotectant solution containing the reservoir solution supplemented with 20% (v/v) glycerol for 5 s. Diffraction data were recorded on Pilatus 6 M and were processed using the HKL2000 program [ 16 ].…”