The C‐terminal flexible region of branched‐chain polyamine synthase facilitates substrate specificity and catalysis

Branched‐chain polyamine synthase (BpsA) catalyzes sequential aminopropyl transfer from the donor, decarboxylated S ‐adenosylmethionine (dc SAM ), to the acceptor, linear‐chain polyamine, resulting in the production of a quaternary‐branched polyamine via tertiary branched polyamine intermediates. Here, we analyzed the catalytic properties and X‐ray crystal structure of Tth ‐BpsA from Thermus thermophilus and compared them with those of Tk ‐BpsA...