STRUCTURAL-ANALYSIS AND COMPARISON OF THE C-TERMINAL TRANSPORT SIGNALDOMAINS OF HEMOLYSIN-A AND LEUKOTOXIN-A

NMR spectroscopy was used to study the structure of the C-terminal sig nal sequences of the bacterial toxins, hemolysin A(HlyA) and leukotoxi n A (LktA), The two signals share little sequence homology; however, b oth can direct toxin transport,vith equal efficiency, We report here t hat in a membrane mimetic environment both peptides form two short non -interacting alpha-helices separated by a short loop, This higher orde r structure may be a common feature of C-terminal signals and may be r equired for interaction with the membrane associated transporter compl ex.