Issues

Ester-bonds linking Thr12, Thr14, Ser20 and Ser22 of ubiquitin to the C-terminal carboxylate of another ubiquitin are formed during immune signalling. The image shows the structure of ubiquitin with lysine residues (blue) known to be modified by ubiquitin and the new serine and threonine linkage sites (green). For more information, see the article by McCrory and colleagues (pp. 2419–2431). The image is provided by Philip Cohen.