1.3.1.104 both free form and complexed with NADP+ and inhibitor triclosan, to 2.2 and 1.8 A resolution, respectively. The substrate-binding region in the apo-FabL structure is found in the open form. In addition, the beta4-alpha5 and beta5-alpha7 regions, which include the catalytic residues as well as the cofactor binding residues, get collapsed into the pocket. These differences result in a tetrameric arrangement totally different from NADH-dependent isoform FabI 1.3.1.104 to 2.5 A resolution. Hexagonal space group P622, with unit-cell parameters a = b = 139.56, c = 62.75 A , alpha = beta = 90, gamma = 120°