Speaker
Description
Photoreceptor proteins utilise the absorption of light to elicit a biological response in a variety of processes, including vision, circadian rhythms and plant development. The focus of current research is the understanding of how the initial photochemical events at the receptor's chromophore funnel through space and time into the desired photobiological event.
In order to visualise photoreceptor proteins in action, a particularly powerful approach is to integrate results from various time-resolved structural biology approaches. Time-resolved serial femtosecond crystallography at XFELs provides atomic resolution structural snapshots of photo-intermediates at physiological (room) temperatures. A potential disadvantage of this approach is the possible interference of structural changes with crystal packing. Time-resolved X-ray solution scattering overcomes this limitation, provides kinetic information on photo-intermediates but the structural information is of low spatial resolution. Time-resolved single particle cryo-EM also provides an atomic-resolution view of structural changes not limited by crystal packing but involves data collection at non-physiological (cryo) temperatures. The merits of a synergistic implementation of time-resolved structural biology approaches will be exemplified by a recent study that investigates a vitamin B12-dependent photoreceptor.