Volume 23, Issue 4, Pages 462-471 (April 2016) Biochemical Dissection of the Natural Diversification of Microcystin Provides Lessons for Synthetic Biology of NRPS  Sabine Meyer, Jan-Christoph Kehr, Andi Mainz, Daniel Dehm, Daniel Petras, Roderich D. Süssmuth, Elke Dittmann  Cell Chemical Biology  Volume 23, Issue 4, Pages 462-471 (April 2016) DOI: 10.1016/j.chembiol.2016.03.011 Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 1 Structure of Microcystin-LR and Alternative Amino Acids Detected at Positions 2 and 4 in Other Microcystin Congeners Cell Chemical Biology 2016 23, 462-471DOI: (10.1016/j.chembiol.2016.03.011) Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 2 Intragenomic Recombination of MC Biosynthesis Genes and Consequences for Microcystin Production In Vivo (A) Schematic representation of MC biosynthesis gene cluster in Microcystis. A domains activating substrates for positions 1–7 are shown as white boxes. The recombination event (RCE) reported for mcyC (highlighted in blue) and mcyB (highlighted in green) is indicated by an arrow. (B) Magnification of the recombination event that has occurred between A3 and A9 motifs of McyC and McyB, respectively. Sequences of strains used for the alignment are listed in Table S2. (C) MC production profile for a representative strain with a B-like McyB type, PCC 7806 and a strain with a McyB/McyC hybrid A domain, NIES 843. Bars represent total MC contents. Differently shaded subsets correspond to quotas of individual MC congeners. MC-LR, -RR, -YR indicate MC variants containing Leu, Arg, and Tyr at position 2 and Arg at position 4, respectively. HL, high light of 250 μmol photons m−2 s−1; LL, low light of 16 μmol photons m−2 s−1. MC content was normalized to chlorophyll a (Chla) as a measure of cell density. Error bars indicate SD from the mean of three biological replicates. Cell Chemical Biology 2016 23, 462-471DOI: (10.1016/j.chembiol.2016.03.011) Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 3 Amino Acid Activation Profiles of McyB and McyC Di-domain and Tri-domain Fragments and a Truncated Tri-domain Variant (A) In vitro activation profiles of A-PCP di-domains. (B) In vitro activation profiles of C*-A-PCP tri-domains that include the C-terminal subdomain of the C domain CCTD. (C) In vitro activation profiles of C-A-PCP tri-domains. The hybrid character of the C-like McyB of NIES 843 is indicated by different gray shades that correspond to the same domain types of ancestor modules. Amino acid activation profiles were determined using an ATP-PPi exchange assay. The preferred substrate was set to 100%. Error bars indicate SD from the mean of two technical replicates. Cell Chemical Biology 2016 23, 462-471DOI: (10.1016/j.chembiol.2016.03.011) Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 4 Impact of Single Amino Acid Substitutions Observed in Natural Strains for McyB C-like Modules on the Specificity Profile See Figure S1 for alignments of sequences. Amino acid activation profiles were determined using an ATP-PPi exchange assay. Amino acids showing the strongest activation were set to 100%. (A) Wild-type protein McyB1 of NIES843. (B) G669V mutant of NIES843. (C) E770D mutant of NIES843. (D) G669V/E770D double mutant of NIES843. Error bars indicate SD from the mean of two technical replicates. Cell Chemical Biology 2016 23, 462-471DOI: (10.1016/j.chembiol.2016.03.011) Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 5 Impact of Single Amino Acid Substitutions on the Specificity Profile of McyC See Figure S1 for alignments of sequences. Amino acid activation profiles were determined using an ATP-PPi exchange assay. Amino acids showing the strongest activation were set to 100%. (A) Wild-type protein McyC of PCC 7806. (B) V674G mutant. (C) D775E mutant. (D) V674G/D775E double mutant. Error bars indicate SD from the mean of two technical replicates. Cell Chemical Biology 2016 23, 462-471DOI: (10.1016/j.chembiol.2016.03.011) Copyright © 2016 Elsevier Ltd Terms and Conditions

Cell Chemical Biology 2016 23, 462-471DOI: (10. 1016/j. chembiol. 2016 Copyright © 2016 Elsevier Ltd Terms and Conditions