Welcome to I04-1

In the past decade, technologies such as robotics, improved synchrotron facilities, powerful computing systems and advancement in phasing algorithms have enabled protein structures to be solved more rapidly. In academic research, this ‘high-throughput’ crystallography led to the birth of structure genomic consortiums all around the world, with structural biologists now foreseeing the possibility of knowing the three-dimensional structures of proteins of an entire genome. In the case of ligand binding studies, when the structure of the protein of interest is already available, subsequent structures in the presence of ligand molecules can be rapidly obtained using molecular replacement (MR). The structural information describes protein-ligand interactions at an atomic level and is important in understanding complex biological systems, their functions and regulation mechanisms. In the pharmaceutical industry, this information often allows a more rational approach to drug design and leads to an increased number of structure/fragment-based drug discovery programs.

I04-1 is dedicated to high-throughput data collection for rapid structure solution using MR method. As more structures become available in databases, MR is the most used method for the structure solution of proteins. The wavelength of the I04-1 beamline is fixed at 0.9163 Å (energy of 13530 eV). The beamline will also be fully automated with a sample changer robot, automated crystal alignment, data collection and processing.

Optionally, single anomalous diffraction (SAD) experiments are possible since anomalous signals of several heavy atoms can still be measured at this wavelength. Finally, an X-ray fluorescence detector will be available to establish the metal ions footprint of the sample.

Please discuss your requirements with a member of the beamline team before your experiment.

 I04-1 wavelength will be fixed at the Bromine K edge (E = 13530 eV, λ = 0.9163 Å). At this wavelength, a strong anomalous signal can be measured for most commonly-used heavy atom derivatives. Therefore, for those elements, single anomalous diffraction (SAD) experiments are possible.

Estimated anomalous difference at 0.92Å resolution for common elements

* Assuming 1 fully occupied heavy atom site per 300 residues for all elements except Se (1/42 heavy atoms/residue) and using the formula:

ΔF/F=sqrt(Nanomalous/2)*2f''/avg(Fp)=sqrt(Nano/2)*2f''/sqrt(346Nresidues)=2f'' * sqrt(1/692) * sqrt(Nano/Nresid) derived from Smith, J., Curr. Opin. Struct. Biol. vol1, p1002 (1991).