(A) Module and domain architecture of selected NRPSs. (B) Inferred phylogeny using the Neighbor-Joining method (Saitou and Nei 1987) of selected M. marinum condensation domains based on aligned predicted amino acid sequences. Different colors highlight condensation domains within an operon. Replicate trees in which the associated domains clustered together on <80% of occasions in a bootstrap test (10,000 replicates) are indicated. The scale is the number of amino acid substitutions per site. All positions containing gaps and missing data were eliminated from the data set.