Integrated analysis of isopentenyl pyrophosphate (IPP) toxicity in isoprenoid-producing Escherichia coli

Journal Article · Tue May 01 00:00:00 EDT 2018 · Metabolic Engineering

DOI:https://doi.org/10.1016/j.ymben.2018.03.004· OSTI ID:1512692

George, Kevin W. ^[1]; Thompson, Mitchell G. ^[1]; Kim, Joonhoon ^[2]; Baidoo, Edward ^[1]; Wang, George ^[1]; Benites, Veronica ^[1]; Petzold, Christopher J. ^[1]; Chan, Leanne ^[1]; Yilmaz, Suzan ^[1]; Turhanen, Petri ^[3]; Adams, Paul ^[4]; Keasling, Jay D. ^[5]; Lee, Taek Soon ^[1]

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1. Lawrence Berkeley National Laboratory
2. BATTELLE (PACIFIC NW LAB)
3. University of Eastern Finland
4. Joint BioEnergy Institute
5. Lawrence Berkley National Lab

Isopentenyl pyrophosphate (IPP) toxicity presents a challenge in engineered microbial systems since its formation is unavoidable in terpene biosynthesis. In this work, we develop an experimental platform to study IPP toxicity in isoprenol-producing Escherichia coli. We first characterize the physiological response to IPP accumulation, demonstrating that elevated IPP levels are linked to growth inhibition, reduced cell viability, and plasmid instability. We show that IPP toxicity selects for pathway “breakage”, using proteomics to identify a reduction in phosphomevalonate kinase (PMK) as a probable recovery mechanism. Next, using multi-omics data, we demonstrate that endogenous E. coli metabolism is globally impacted by IPP accumulation, which slows nutrient uptake, decreases ATP levels, and perturbs nucleotide metabolism. We also observe the extracellular accumulation of IPP and present preliminary evidence that IPP can be transported by E. coli, findings that might be broadly relevant for the study of isoprenoid biosynthesis. Finally, we discover that IPP accumulation leads to the formation of ApppI, a nucleotide analog of IPP that may contribute to observed toxicity phenotypes. This comprehensive assessment of IPP stress suggests potential strategies for the alleviation of prenyl diphosphate toxicity and highlights possible engineering targets for improved IPP flux and high titer isoprenoid production.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1512692
• Report Number(s): PNNL-SA-138198
• Journal Information: Metabolic Engineering, Vol. 47
• Country of Publication: United States
• Language: English