FIG. 2.

Global tree of collected ABC modules. The phylogenetic tree encompasses cyanobacterial ABC proteins (boldface), ABC proteins implicated in the transport of NRPs/PKs (underlined), and other representatives from across the ABC transporter superfamily. The major subdivisions of the tree are indicated according to the nomenclature given in the text (ABC-A, export systems; ABC-B, import systems). See Table 1 for a detailed list of modules present in each cluster. The scale bar corresponds to 10% divergence between sequences.