FIG. 5.

Characterization of the NdaA condensation domain. A) Phylogenetic analysis of the amino acid sequences of the condensation (C) domains from nodularin synthetase of N. spumigena NSOR10, microcystin synthetases of M. aeruginosa PCC7806 and P. agardhii CYA126/8, and gramicidin S synthetase (GrsA) of Bacillus brevis ATCC 9999. The sequence alignment and phylogenetic tree were created by using Pileup and ClustalX from GCG (40, 48). The scale bar represents one substitution per 10 amino acids. Significant bootstrap values calculated from 1,000 bootstrap trees are indicated at the nodes (11). B) Diagram of the proposed deletion of the second and first NRPS modules of McyA and McyB, respectively. A, adenylation; C, condensation; E, epimerization; M, N-methyltransferase. PCP domains are shown in black; the NdaA condensation domain linker region is shown in white.