Rossmann fold. It is found in enzymes (such as dehydrogenases or kinases) that bind molecules such as ATP or NAD+/NADH. Rossmann then turned to viruses, spending a sabbatical in 1971 with Bror Strandberg in Uppsala, Sweden, working on the structure of the satellite tobacco necrosis virus. From 1972 to 1980 Rossmann and his team worked on the southern bean mosaic virus. This required developing new software and adapting existing software for Fourier transforms. It was found that this virus had a similar "jelly roll fold" to that found previously in the tomato bushy stunt virus, which at the time was a surprise. In the early 1980s Rossmann began working on picornaviruses, and chose HRV14, one of the viruses that cause the common cold. Part of the problem was that it was very difficult at the time to produce milligram quantities of an animal virus, as needed for the X-ray crystallography. Rossmann pushed for the purchase by Purdue of a Cyber 205 supercomputer, capable of delivering hundreds of megaflops. After vectorizing the computer programs, calculations that had taken six weeks with the southern bean mosaic virus now took, for HRV14, only a fraction of a day. In 1985, he published his team's mapping in the journal Nature. The breakthrough nature of this result was such that the National Science Foundation, which provided partial funding for the research, saw fit to organize a press conference, and the news travelled in the general press. This work laid the foundation for a molecular understanding of cell entry of enteroviruses and for the development of capsid-binding inhibitors against a broad range of enteroviruses. After the success with the first cold virus, work was done on alphaviruses and flaviviruses. Using cryo-electron microscopy, in 2016 his lab reported the first known structure of the Zika virus, responsible for a severe epidemic at the time. This work was made possible by more than one decade of studies on related mosquito borne flaviviruses, including dengue virus, using a combination of cryo-electron microscopy and X-ray crystallography. Rossmann also had a long-term interest in complicated viral machines. These are exemplified by bacteriophage T4 and nucleocytoplasmic large DNA viruses, also referred to as giant viruses. The determination of an atomic structure of Paramecium bursaria chlorella virus 1 that infects algae has opened up new possibilities for studying giant viruses at the atomic level. Life and hobbies Rossmann was an avid hiker and