Louise Johnson (1940–2012) Biophysicist Who Helped to Establish the Field of Structural Biology

COMMENT OBITUARY Louise Johnson (1940–2012) Biophysicist who helped to establish the field of structural biology.

ouise Johnson transformed our under- Laboratory of Molecular Biophysics at the Johnson’s many achievements included standing of how complex enzymes and University of Oxford. establishing the structure of a large and other proteins work. By combining her I first encountered Johnson about ten complex enzyme called glycogen phos- Lin-depth knowledge of X-ray crystallogra- years later. I was a first-year undergradu- phorylase. Present in muscle, this enzyme phy with a long-standing interest in bio- ate at Oxford studying biochemistry, and turns inert glycogen into the sugar needed chemistry, she helped to launch structural my tutor sent me to her to learn the basics to power physical activity. Johnson showed biology as a new discipline. how the addition or removal Johnson, who died on of phosphate groups from 25 September, was born the protein regulates its on 26 September 1940 activity. (Phosphorylation in Worcester, UK. She has since turned out to be a attended Wimbledon High key form of regulation in all School for Girls in Lon- sorts of cellular processes.) don and then completed a She subsequently carried

degree in physics at Univer- out a set of groundbreak- IMAGES A.-K. PURKISS, WELLCOME sity College London. ing studies on proteins that In 1962, Johnson started have key roles in the regula- a PhD at London’s Royal tion of cell division. Institution — working In all this work, Johnson under David Phillips, a pio- demonstrated that X-ray neer of protein crystallogra- crystallography could reveal phy. There she contributed detailed catalytic and regu- to studies on lysozyme, an latory mechanisms, and can enzyme that is abundant in potentially unmask how various substances, such as large proteins work as com- tears and egg whites, and plex biochemical machines. which breaks down the cell Her 1976 book Protein Crys- walls of bacteria. Even at tallography (co-authored this early stage in her career, with Tom Blundell) was for Johnson was not interested many years the classic text- in just working out struc- book on the topic. tures, but wanted to use Johnson received many an understanding of structure to uncover of how protein structures are determined. honours in recognition of her work, includ- fundamental biochemical mechanisms. Instead of providing me with a standard ing being made a fellow of the British Royal By firing X-rays at the crystallized pro- textbook description, Johnson threw me in Society in 1990 and a foreign associate of the tein and studying the angles and intensities at the deep end. I was soon working through US National Academy of Sciences in 2011. of the diffracted beams, Phillips estab- Fourier transforms — mathematical descrip- Louise was very supportive of young lished lysozyme’s structure in 1965. This tions of what happens when X-rays are scientists, particularly women. Married, was the second protein structure to be scattered by protein molecules. with two children, to physicist and Nobel solved by X-ray crystallography (the first In 1990, Johnson was made the David laureate Abdus Salam, she understood the was myoglobin, found in muscle). John- Phillips Professor of Molecular Biophysics, challenges of juggling a scientific career son’s contribution was to work out what and she remained in this post until her with looking after a family. A quiet and kind lysozyme looked like when it was bound retirement. By this time, the Laboratory person, she directed her students and fellow to N-acetyl-glucosamine, a component of of Molecular Biophysics had become part researchers carefully but gently. The harsh- bacterial cell walls. Johnson and Phillips’s of Oxford’s biochemistry department. est comment I remember receiving from work led to the first structural evidence From 2003, Johnson combined her her — on my hastily written grant proposal that a substrate slots into an enzyme, much position at Oxford with leading the develop- — was “perhaps a little nebulous”. She was a as a key fits into a lock. ment of the UK national synchrotron, the source of inspiration to all around her, and After her PhD, Johnson spent a year at Diamond Light Source near Didcot. The will be greatly missed. ■ Yale University in New Haven, Connecti- largest science facility to have been built cut, where she worked as a postdoc with bio- in the country for more than 40 years, the Mark Sansom is the David Phillips physicist Fred Richards. Here she uncovered synchrotron produces beams of light that Professor of Molecular Biophysics in the the structure of the enzyme ribonuclease S, can be used to investigate the structure and Department of Biochemistry, University showing that X-ray crystallography could be properties of materials including proteins. I of Oxford, Oxford OX1 3QU, UK. He was applied to proteins that were more complex recall accompanying her (both of us wearing Louise Johnson’s graduate student from than lysozyme. In 1967, she returned to the hard hats and boots) as she showed me the 1979 to 1983. United Kingdom and rejoined Phillips in the nascent facility with evident pride. e-mail: [email protected]