Reaction kinetic analysis of the 3-hydroxypropionate/4-hydroxybutyrate CO₂ fixation cycle in extremely thermoacidophilic archaea

Journal Article · Wed Oct 19 00:00:00 EDT 2016 · Metabolic Engineering

DOI:https://doi.org/10.1016/j.ymben.2016.10.009· OSTI ID:1422400

Loder, Andrew J. ^[1]; Han, Yejun ^[2]; Hawkins, Aaron B. ^[3]; Lian, Hong ^[4]; Lipscomb, Gina L. ^[5]; Schut, Gerrit J. ^[5]; Keller, Matthew W. ^[5]; Adams, Michael W. W. ^[5]; Kelly, Robert M. ^[6]

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1. North Carolina State Univ., Raleigh, NC (United States); Novozymes North America Inc., Franklinton, NC (United States); North Carolina State University
2. North Carolina State Univ., Raleigh, NC (United States); Chinese Academy of Sciences, Beijing (China)
3. North Carolina State Univ., Raleigh, NC (United States); Novozymes North America Inc., Franklinton, NC (United States)
4. North Carolina State Univ., Raleigh, NC (United States); Xiamen Univ., Fujan Province (China)
5. Univ. of Georgia, Athens, GA (United States)
6. North Carolina State Univ., Raleigh, NC (United States)

Here, the 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) cycle fixes CO₂ in extremely thermoacidophilic archaea and holds promise for metabolic engineering because of its thermostability and potentially rapid pathway kinetics. A reaction kinetics model was developed to examine the biological and biotechnological attributes of the 3HP/4HB cycle as it operates in Metallosphaera sedula, based on previous information as well as on kinetic parameters determined here for recombinant versions of five of the cycle enzymes (malonyl-CoA/succinyl-CoA reductase, 3-hydroxypropionyl-CoA synthetase, 3-hydroxypropionyl-CoA dehydratase, acryloyl-CoA reductase, and succinic semialdehyde reductase). The model correctly predicted previously observed features of the cycle: the 35%–65% split of carbon flux through the acetyl-CoA and succinate branches, the high abundance and relative ratio of acetyl-CoA/propionyl-CoA carboxylase (ACC) and MCR, and the significance of ACC and hydroxybutyryl-CoA synthetase (HBCS) as regulated control points for the cycle. The model was then used to assess metabolic engineering strategies for incorporating CO₂ into chemical intermediates and products of biotechnological importance: acetyl-CoA, succinate, and 3-hydroxyproprionate.

• Research Organization: North Carolina State Univ., Raleigh, NC (United States)
• Sponsoring Organization: USDOE; USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: AR0000081
• OSTI ID: 1422400
• Alternate ID(s): OSTI ID: 1410825
• Journal Information: Metabolic Engineering, Journal Name: Metabolic Engineering Journal Issue: C Vol. 38; ISSN 1096-7176
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

3-hydroxypropionate
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
4-hydroxybutyrate
CO2 fixation
Metallosphaera sedula