Fig. 3. Ribbon plot of ParM in the empty form (left) and the ADP-containing form (right). ParM, as a member of the actin family of proteins, consists of two domains (I and II), which are divided into two subdomains (A and B). ADP binds in the interdomain cleft, which closes upon nucleotide binding through a rigid body movement of domains I and II. Images were created with MOLSCRIPT and RASTER3D (Kraulis, 1991; Merritt and Bacon, 1997).