초록
<P><B>Abstract</B></P><P>Putrescine transaminase (pATA; EC 2.6.1.82) catalyzes the transfer of an amino group from terminal diamine donor molecules to keto acid acceptors by using pyridoxal‐5′‐phosphate as a cofactor. The <I>ygjG</I> genes from <I>Escherichia coli</I> K12, <I>Bacillus megaterium</I>, and <I>Bacillus mycoides</I> were successfully cloned and expressed in <I>E. coli</I> BL21(DE3) cells. The three putrescine transaminases were all shown to prefer diaminoalkanes as substrates and thereby generated cyclic imines from the ω‐amino aldehyde intermediates. The addition of a mild chemical reducing agent rapidly reduced the imine intermediate in situ to furnish a range of <I>N</I>‐heterocycle products. We applied pATA in a biomimetic synthesis of 2,3‐dihydro‐1<I>H</I>‐indolizinium‐containing targets, notably the bioactive alkaloid ficuseptine.</P>