S C

IE N

T IF

IC H

IG H

LI G

H T

S S

T R

U C

T U

R A

L B

IO LO

G Y

3 5 I H I G H L I G H T S 2 0 2 2

modelling in solution at BM29 or single-particle cryo-EM analysis at CM01.

The Solution to Structure (SOS) service provided by CM01 has also started to bear fruit, with the first successful results this year. A pipeline mainly intended for users with limited access to cryo-EM, it can start either from a liquid sample of high enough quality based on biochemistry evidence or from frozen cryo-EM grids that are not yet screened. Furthermore, the establishment of a second cryo-EM (CM02) as a French collaborative research group (CRG) beamline in the autumn of 2023 will supplement and complement the activities of the highly over- subscribed CM01 and will provide access for experiments exploiting cryo-electron tomography (cryo-ET).

In parallel to our commitment to provide a comprehensive beamline portfolio for integrative structural determination, we are continuing to develop an ambitious in-house research programme, which helps us to assist our user community needs by providing expertise and experience in sample preparation and characterisation, and advanced synchrotron tools. The refurbishment of the molecular biology laboratory (CIBB lab) jointly with the Partnership for Structural Biology (PSB) offers a unique environment for state-of-the-art integrated structural biology platforms on the EPN campus, a successful collaboration that celebrates its 20th anniversary this year.

The work presented in this chapter represents only a very small fraction of the science reported by the Structural Biology user community, but it illustrates the trends observed in recent years towards the application of integrative structural biology to unravel major fundamental biology challenges. Two articles provide structural insights into the catalytic properties of RNA molecules (Höbartner et al., page 36; Weixlbaumer et al., page 50), reinforcing the RNA world hypothesis in the development

of early life on the planet. Another article sheds light on the molecular mechanisms of photosynthetic oxygen adaption in the evolution of complex life forms on earth (Hochberg et al., page 41). Three more articles focus on the structural studies of key regulatory viral proteins to deepen our understanding in the infection cycles of the tick-borne encephalitis flavivirus (Rey et al., page 37), the Epstein-Barr herpesvirus (Petosa et al., page 39) or the coronavirus (Hamley et al., page 44). An article by Poelarends et al. (page 47) demonstrates the power of directed evolution of natural aldolase enzymes to develop novel catalysts for biotechnological applications. Furthermore, the underlying catalytic activity mechanism of a mitochondrial kinase is elucidated in the article of Hoxhaj et al. (page 45). A cancer biology study by Shakked et al. (page 42) paves the way for structure- based drug discovery to target the tumour suppressor p53 protein for potential cancer therapy. Particularly noteworthy is the work of Jensen et al. on the visualisation of protein breathing motions associated with ring flipping (page 48), with implications for protein design and structure prediction. Overall, this ensemble of articles represents the extremely high-quality research over a broad range of topics carried out by our user community.

On a final note, after more than 30 years of service to the ESRF, Gordon Leonard retired as Head of the Structural Biology group in December. On behalf of the whole group, we express our deep gratitude for his invaluable work over these years and for successfully steering the group through many difficult waters, including the great challenges posed by the EBS upgrade. Mindful of the legacy we receive and of the high standards set, we will do our best to make the Structural Biology beamlines and user operation vibrant and dynamic and be an enviable model for synchrotrons worldwide.

M. SOLER LOPEZ AND M. NANAO