Figure 4.
Autoradiogram of TaC and TaF activity. (A) 2-14C-Ac-S-TaB (top) or 2-14C-Mal-S-TaE (bottom) was combined with Acac-S-Ta1-T6 in the presence or absence of TaC or TaF. Reaction aliquots were withdrawn at 0, 1, 4, and 8 minutes and subjected to denaturing gel electrophoresis and autoradiography. The phosphopantetheinyl transferase Sfp remaining from in situ generation of the acyl-holo-thiolation domains is visible. (B) 2-14C-Ac-S-TaB was combined with Acac-S-Ta1-T7 (predicted not to serve as a β-branch acceptor) or Acac-S-Ta1-T8 (predicted to serve as the C12 β-ethyl branch acceptor) in the presence (+) or absence (−) of TaC for five minutes. The reaction mixtures were subjected to denaturing gel electrophoresis and autoradiography.