5D9C: Luciferin-regenerating Enzyme Solved By Siras Using Xfel (refined Against Hg Derivative Data)

Serial femtosecond crystallography (SFX) with X-ray free electron lasers (XFELs) holds great potential for structure determination of challenging proteins that are not amenable to producing large well diffracting crystals. Efficient de novo phasing methods are highly demanding and as such most SFX structures have been determined by molecular replacement methods. Here we employed single isomorphous replacement with anomalous scattering (SIRAS) for phasing and demonstrate successful application to SFX de novo phasing. Only about 20,000 patterns in total were needed for SIRAS phasing while single wavelength anomalous dispersion (SAD) phasing was unsuccessful with more than 80,000 patterns of derivative crystals. We employed high energy X-rays from SACLA (12.6 keV) to take advantage of the large anomalous enhancement near the LIII absorption edge of Hg, which is one of the most widely used heavy atoms for phasing in conventional protein crystallography. Hard XFEL is of benefit for de novo phasing in the use of routinely used heavy atoms and high resolution data collection.
PDB ID: 5D9CDownload
MMDB ID: 132979
PDB Deposition Date: 2015/8/18
Updated in MMDB: 2015/09
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Source Organism:
Similar Structures:
Biological Unit for 5D9C: monomeric; determined by author
Molecular Components in 5D9C
Label Count Molecule
Protein (1 molecule)
Luciferin Regenerating Enzyme
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

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