Three-dimensional models of the filamin A rod domain repeat unit 23, generated on the basis of the homologous structures of the 4th (Fucini et al. 1997) and 5th (McCoy et al. 1999) module of the F-Actin Cross-Linking Gelation Factor (Abp-120) by use of Swiss-Model (Guex and Peitsch 1997; Protein Data Bank). a, Ribbon model of a repeat unit showing, in cyan, the regular position of the strand deleted in the shortened protein. Amino- and carboxyterminal ends of the repeat are marked by N- and -C, respectively. b, Model showing the respective position of the leucine residue corresponding to position 2439 depicted in cyan. It resides in a hydrophobic surface cluster. Nonpolar residues are shown in red.