... contacts to the pantetheine moiety of CoA at the outer edge of the tunnel. Water molecules are also present in the pantetheine binding tunnel, both in the unliganded and liganded states [2,11]. There ... different conformations; in the unliganded form, it points away from the tunnel, and, in the liganded conformation, it points into the tunnel,interacting with the N4 atom of the CoA substrate[2,10]. ... for exam-ple, Km and kcat are 73 lm and 469 ⁄ s for AcAc-SPP,whereas they are 24 lm and 465 ⁄ s, respectively, forAcAc-CoA. In the crystal structure, the binding modesof the reactive sulfur...