Abstract
Two new macromolecular crystallography (MX) beamlines at the National Synchrotron Light Source II, FMX and AMX, opened for general user operation in February 2017 [Schneider et al. (2013). J. Phys. Conf. Ser. 425, 012003; Fuchs et al. (2014). J. Phys. Conf. Ser. 493, 012021; Fuchs et al. (2016). AIP Conf. Proc. SRI2015, 1741, 030006]. FMX, the micro-focusing Frontier MX beamline in sector 17-ID-2 at NSLS-II, covers a 5-30 keV photon energy range and delivers a flux of 4.0 × 1012 photons s-1 at 1 Å into a 1 µm × 1.5 µm to 10 µm × 10 µm (V × H) variable focus, expected to reach 5 × 1012 photons s-1 at final storage-ring current. This flux density surpasses most MX beamlines by nearly two orders of magnitude. The high brightness and microbeam capability of FMX are focused on solving difficult crystallographic challenges. The beamline's flexible design supports a wide range of structure determination methods - serial crystallography on micrometre-sized crystals, raster optimization of diffraction from inhomogeneous crystals, high-resolution data collection from large-unit-cell crystals, room-temperature data collection for crystals that are difficult to freeze and for studying conformational dynamics, and fully automated data collection for sample-screening and ligand-binding studies. FMX's high dose rate reduces data collection times for applications like serial crystallography to minutes rather than hours. With associated sample lifetimes as short as a few milliseconds, new rapid sample-delivery methods have been implemented, such as an ultra-high-speed high-precision piezo scanner goniometer [Gao et al. (2018). J. Synchrotron Rad. 25, 1362-1370], new microcrystal-optimized micromesh well sample holders [Guo et al. (2018). IUCrJ, 5, 238-246] and highly viscous media injectors [Weierstall et al. (2014). Nat. Commun. 5, 3309]. The new beamline pushes the frontier of synchrotron crystallography and enables users to determine structures from difficult-to-crystallize targets like membrane proteins, using previously intractable crystals of a few micrometres in size, and to obtain quality structures from irregular larger crystals.
Highlights
In recent years, microcrystallography has undergone revolutionary developments that have greatly widened its appeal for structure determination of challenging proteins (Smith et al, 2012; Owen et al, 2016; Yamamoto et al, 2017)
Sample delivery beyond standard cryocrystallography can be tailored to the protein-crystallization environment by choosing between ultra-fast rastering serial microcrystallography, room-temperature in situ crystallography or serial crystallography in a lipidic cubic phase (LCP) injector
Key elements to achieving these goals are a staggering of the optical components between AMX and FMX, a pair of horizontal deflection mirrors in the AMX beam path, the use of long mirrors bent by bimorph piezoelectric transducers, a single-stage vertical and two-stage horizontal focusing scheme, and a horizontal-bounce double-crystal monochromator (HDCM) for increased stability (Fig. 1)
Summary
Microcrystallography has undergone revolutionary developments that have greatly widened its appeal for structure determination of challenging proteins (Smith et al, 2012; Owen et al, 2016; Yamamoto et al, 2017). The new Frontier Microfocusing Macromolecular Crystallography (FMX) beamline at the National Synchrotron Light Source II at Brookhaven National Laboratory (BNL) (Fuchs et al, 2014, 2016) delivers a beam of unprecedented brightness, stability and versatility, with a beam size of 1 to 10 mm and a flux of 4.0 Â 1012 photons sÀ1 at a wavelength of 1 A. Automation of all crucial steps of the experiment greatly increases experiment speed: high-throughput sample-mounting robotics, high-speed raster-scan location of microcrystals, and automated data-processing pipelines supported by high-performance computing. The design of the FMX optical system delivers a beam that brings NSLS-II’s unprecedented emittance (Smaluk et al, 2019) to the crystal, and its experimental station handles this crystal with the required precision, speed and flexibility. The high dose rates require a reconsideration of established designs, such as the need for a sub-millisecond shutter even for shutter-less data acquisition
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
