The back cover picture shows the inhibition of SecA, a key enzyme in the bacterial general secretion (Sec) pathway. SecA is essential for bacterial growth and as such represents an ideal target for antibacterial agents. The fluorescein derivatives shown represent the first sub-micromolar inhibitors of SecA's ATPase activity. For more details, see the Full Paper by Binghe Wang, Phang C. Tai et al. on p. 571 ff.