Nobel for Cryo-EM

The revolution will not be crystallized: a new method sweeps through structural biology. Move over X-ray crystallography. Cryo-electron microscopy is kicking up a storm by revealing the hidden machinery of the cell by bombarding uncrystallized samples flash-frozen to stability. nature

Jacques Dubochet, Joachim Frank and Richard Henderson were awarded the Nobel prize on 4 October, 2017, for their work in developing cryo-electron microscopy. nature

4.9 Å cryo-EM map of the mammalian 39S mitoribosomal subunit. page

Cryo-EM is suited to large, stable molecules that can withstand electron bombardment without jiggling around — so molecular machines, often built from dozens of proteins, are good targets.

None has proved more suitable than ribosomes, which are braced by rigid twists of RNA. In the past couple of years, ‘ribosomania’ has gripped cryo-EM researchers, and various teams have quickly determined and published dozens of cryo-EM structures of ribosomes from a multitude of organisms, including the first high-resolution models of human ribosomes.

Long after digital cameras had taken the world by storm, many electron microscopists still preferred old-fashioned film because it recorded electrons more efficiently than did digital sensors. But, working with microscope manufacturers, the researchers developed a new generation of ‘direct electron detectors’ that vastly outperforms both film and digital-camera detectors.

Available since about 2012, the detectors can capture quick-fire images of an individual molecule at dozens of frames per second. Researchers such as Scheres, meanwhile, have written sophisticated software programs to morph thousands of 2D images into sharp 3D models that, in many cases, match the quality of those deciphered with crystallography.

Richard Henderson talks to Jim Al-Khalili about half a century of problem solving and the bold strategic decisions that led him to be awarded the 2017 Nobel Prize for Chemistry, together with Joaquim Frank and Jacques Dubochet. bbc