Comparison of the known cyanopeptolin operons. The overall structure of cyanopeptolin operons oci from Planktothrix NIES 205 [GenBank: EU109504] and NIVA CYA 116 [GenBank: DQ837301], mcn from Microcystis [GenBank: DQ075244] and apd from Anabaena [GenBank: AJ269505]. Gene names, transcription directions and approximate sizes are indicated above each gene cluster. Adenylation (red), condensation (green), thiolation (yellow), epimerization (turquoise), methyltransferase (blue) sulfotransferase (pink), halogenisation (purple) and termination domains (grey) are shown with their abbreviations. The putative activated amino acids are indicated for each A-domain. Amino acids detected in smaller amounts are beneath the major amino acid. Equivalent modules are depicted in light blue and light orange. The ABC transporter is transcribed in the opposite direction in the oci and mcn operons, and an ABC transporter is predicted downstream of the apd operon.