Experimental phasing opportunities for macromolecular crystallography at very long wavelengths

Journal article

Despite recent advances in cryo-electron microscopy and artificial intelligence-based model predictions, a significant fraction of structure determinations by macromolecular crystallography still requires experimental phasing, usually by means of single-wavelength anomalous diffraction (SAD) techniques. Most synchrotron beamlines provide highly brilliant beams of X-rays of between 0.7 and 2 Å wavelength. Use of longer wavelengths to access the absorption edges of biologically important lighter atoms such as calcium, potassium, chlorine, sulfur and phosphorus for native-SAD phasing is attractive but technically highly challenging. The long-wavelength beamline I23 at Diamond Light Source overcomes these limitations and extends the accessible wavelength range to λ = 5.9 Å. Here we report 22 macromolecular structures solved in this extended wavelength range, using anomalous scattering from a range of elements which demonstrate the routine feasibility of lighter atom phasing. We suggest that, in light of its advantages, long-wavelength crystallography is a compelling option for experimental phasing

Authors: El Omari, K; Duman, R; Mykhaylyk, V; Orr, CM; Latimer-Smith, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Communications Chemistry
• Volume: 6
• Issue: 1
• Pages: 219-219
• Article number: 219
• Publication date: 2023-10-12
• DOI: 10.1038/s42004-023-01014-0
• EISSN: 2399-3669
• ISSN: 2399-3669
• Language: English
• Keywords: Diamond; Materials science; Anomalous scattering; Diffraction; Chemistry; Crystallography; Physics; Optics; Optoelectronics; Phaser; Synchrotron; Wavelength