Optimization of the heme biosynthesis pathway for the production of 5-aminolevulinic acid in Escherichia coli.

ABSTRACT: 5-Aminolevulinic acid (ALA), the committed intermediate of the heme biosynthesis pathway, shows significant promise for cancer treatment. Here, we identified that in addition to hemA and hemL, hemB, hemD, hemF, hemG and hemH are also the major regulatory targets of the heme biosynthesis pathway. Interestingly, up-regulation of hemD and hemF benefited ALA accumulation whereas overexpression of hemB, hemG and hemH diminished ALA accumulation. Accordingly, by combinatorial overexpression of the hemA, hemL, hemD and hemF with different copy-number plasmids, the titer of ALA was improved to 3.25 g l(-1). Furthermore, in combination with transcriptional and enzymatic analysis, we demonstrated that ALA dehydratase (HemB) encoded by hemB is feedback inhibited by the downstream intermediate protopo

SUBMITTER: Zhang J 

PROVIDER: S-EPMC4341193 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature