On The Cover: Structural model of the redox complex between cytochrome c552 (green) and the ba3 oxidase (yellow/blue) of Thermus thermophilus as derived from NMR chemical shift perturbation experiments performed at 900 MHz. Heme moieties (red/orange) and copper ions (magenta) act as electron donors and/or acceptors. For details see the article by Muresanu et al., pages 14503–14513.