Format

Send to

Choose Destination
BMC Plant Biol. 2018 Jun 15;18(1):118. doi: 10.1186/s12870-018-1315-4.

Molecular and biochemical characterization of a novel isoprene synthase from Metrosideros polymorpha.

Author information

1
Synthetic Biology and Bioengineering Research Center, KRIBB, Daejeon, 34141, Republic of Korea.
2
Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, 34113, Republic of Korea.
3
Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, 34113, Republic of Korea.
4
Synthetic Biology and Bioengineering Research Center, KRIBB, Daejeon, 34141, Republic of Korea. sglee@kribb.re.kr.
5
Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, 34113, Republic of Korea. sglee@kribb.re.kr.

Abstract

BACKGROUND:

Isoprene is a five-carbon chemical that is an important starting material for the synthesis of rubber, elastomers, and medicines. Although many plants produce huge amounts of isoprene, it is very difficult to obtain isoprene directly from plants because of its high volatility and increasing environmental regulations. Over the last decade, microorganisms have emerged as a promising alternative host for efficient and sustainable bioisoprene production. Isoprene synthase (IspS) has received much attention for the conversion of isoprene from dimethylallyl diphosphate (DMAPP). Herein, we isolated a highly expressible novel IspS gene from Metrosideros polymorpha (MpIspS), which was cloned and expressed in Escherichia coli, using a plant cDNA library and characterized its molecular and biochemical properties.

RESULTS:

The signal sequence deleted MpIspS was cloned and expressed in E. coli as a 65-kDa monomer. The maximal activity of the purified MpIspS was observed at pH 6.0 and 55 °C in the presence of 5 mM Mn2+. The Km, kcat, and kcat/Km for DMAPP as a substrate were 8.11 mM, 21 min- 1, and 2.59 mM- 1 min- 1, respectively. MpIspS was expressed along with the exogenous mevalonate pathway to produce isoprene in E. coli. The engineered cells produced isoprene concentrations of up to 23.3 mg/L using glycerol as the main carbon source.

CONCLUSION:

MpIspS was expressed in large amounts in E. coli, which led to increased enzymatic activity and resulted in isoprene production in vivo. These results demonstrate a new IspS enzyme that is useful as a key biocatalyst for bioisoprene production in engineered microbes.

KEYWORDS:

DMAPP; Escherichia coli; Isoprene synthase; Mevalonate pathway

PMID:
29902970
PMCID:
PMC6003189
DOI:
10.1186/s12870-018-1315-4
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center