초록
<P>A novel biosynthetic pathway was designed and verified reversely leading to the production of 5-hydroxytryptophan (5-HTP) from glucose. This pathway takes advantage of the relaxed substrate selectivities of relevant enzymes without employing the unstable tryptophan 5-hydroxylase. First, high-titer of 5-HTP was produced from 5-hydroxyanthranilate (5-HI) by the catalysis of <I>E. coli</I> TrpDCBA. Then, a novel salicylate 5-hydroxylase was used to convert the non-natural substrate anthranilate to 5-HI. After that, the production of 5-HI from glucose was achieved and optimized with modular optimization. In the end, we combined the full pathway and adopted a two-stage strategy to realize the <I>de novo</I> production of 5-HTP. This work demonstrated the application of enzyme promiscuity in non-natural pathway design.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/asbcd6/2015/asbcd6.2015.4.issue-5/sb500303q/production/images/medium/sb-2014-00303q_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/sb500303q'>ACS Electronic Supporting Info</A></P>