FIG 6.

Metabolic perturbations in methionine salvage cycle and spermidine synthesis pathway. S-Adenosylmethioninamine, putrescine, and spermidine were analyzed using the RPLC method, while the other metabolites were analyzed by the HILIC method. Metabolites in red boxes indicate increased abundance in PAKpmrB6 and/or PAKpmrB12, while blue boxes indicate decreased abundance compared to that in the wild-type PAK. Metabolites in gray boxes were not detected through either the HILIC or RPLC method. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (Student's t test). Dashed arrow shows the conversion of putrescine to spermidine catalyzed by SpeE in the presence of the cofactor S-adenosylmethioninamine.