Fig. 7. Analysis of the roles of the C- and X-domains within the final NRPS module from balhimycin biosynthesis as assessed through the isolation and analysis of the peptide products formed by the resultant mutant producer strains in which these domains had been removed. Results show that the initial cyclisation step performed by OxyB can occur on the peptide at the hexapeptide stage, which raises the question of cyclisation vs. heptapeptide formation during GPA biosynthesis. NRPS domain descriptions: C, condensation; A, adenylation; PCP, peptidyl carrier protein; X, P450 (Oxy) recruitment; TE, thioesterase.
