Structure determination of in vivo grown nano-crystals using serial synchrotron crystallography with a nano-focused X-ray beam

The emergence of serial crystallography (SX) has changed the feasibility landscape in structural biology, enabling room-temperature (RT) structure determination from micro-crystals and the conduit of time-resolved experiments even on non-reversible biological systems. Among synchrotron beamlines that enabled this shift in paradigm, ID13 stands out for its unmatched brilliance and focusing. A limit was however reached with nanocrystals of the mosquitocidal toxin Cyt1Aa which, before the EBS upgrade, diffracted to 4.5 Å resolution at 100 K on ID13, compared to 1.8 Å resolution at RT at LCLS. As the flux at ID13 is now ~50 times higher, chances are high that higher resolution data can be collected from these crystals at 100 K – and possibly even at RT - using nano-SSX. The goal of our proposal is to verify this hypothesis and benchmark the nano-SSX capabilities of ID13 after the EBS upgrade, thereby assessing whether nano-SSX could lead the future of macromolecular crystallography.