1. The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London, NW7 1AA, UK
2. Formerly Divisions of Virology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
3. Physical Biochemistry, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
4. Department of Medicine, Glycosciences Laboratory, Imperial College London, Du Cane Road, London, W12 0NN, UK