Fig. 6
From: Basidiomycete non-reducing polyketide synthases function independently of SAT domains
LC–MS/MS spectra of the tetraketide pyrone produced by ArmB and ArmBΔSAT in vitro. The spectra were recorded in negative [M – H]− ionization mode. Asterisks denote the parental ions. Calculated masses for the tetraketide pyrone are m/z 173.0551 (13C6-labeled) and m/z 175.0607 (fully 13C8-labeled). Proposed fragments that are compatible with the highlighted mass values (bold) highlighted in light blue. A Analysis of the reactions with ArmB and unlabeled acetyl-CoA and [13C3]malonyl-CoA. B Reaction of ArmBΔSAT with unlabeled acetyl-CoA and [13C3]malonyl-CoA. C Reaction of ArmB with [13C3]malonyl-CoA only. D Reaction of ArmBΔSAT with [13C3]malonyl-CoA only. Mass signals in windows A and B which result from full labeling (.13C8) and which show high intensity in the spectra C and D are highlighted in red. A comprehensive comparison with literature data [46] on LC–MS/MS analyses of the tetraketide pyrone is provided in Additional file 1: Fig. S6