BioChem - DOS

Balanced activation of IspG and IspH to eliminate MEP intermediate accumulation and improve isoprenoids production in Escherichia coli

Metabolic engineering

Li, Qingyan; Fan, Feiyu; Gao, Xiang; Yang, Chen; Bi, Changhao; Tang, Jinlei; Liu, Tao; Zhang, Xueli

<P><B>Abstract</B></P> <P>The MEP pathway genes were modulated to investigate whether there were new rate-limiting steps and toxic intermediates in this pathway. Activating IspG led to significant decrease of cell growth and &beta;-carotene production. It was found that <I>ispG</I> overexpression led to accumulation of intermediate HMBPP, which seriously interfered with synthesis machinery of nucleotide and protein in <I>Escherichia coli</I>. Activation of the downstream enzyme IspH could solve HMBPP accumulation problem and eliminate the negative effects of <I>ispG</I> overexpression. In addition, intermediate MECPP accumulated in the starting strain, while balanced activation of IspG and IspH could push the carbon flux away from MECPP and led to 73% and 77% increase of &beta;-carotene and lycopene titer respectively. Our work for the first time identified HMBPP to be a cytotoxic intermediate in MEP pathway and demonstrated that balanced activation of IspG and IspH could eliminate accumulation of HMBPP and MECPP and improve isoprenoids production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Activating IspG led to decreased cell growth and &beta;-carotene production. </LI> <LI> <I>ispG</I> overexpression led to accumulation of intermediate HMBPP. </LI> <LI> HMBPP accumulation interfered with nucleotide and protein synthesis. </LI> <LI> Balanced activation of IspG and IspH eliminated HMBPP and MECPP accumulation. </LI> <LI> &beta;-carotene titer increased 73% by balanced activation of IspG and IspH. </LI> </UL> </P>

2017

Elsevier

1096-7176

1096-7184

44

pp.13-21

10.1016/j.ymben.2017.08.005

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART79563106

Isoprenoid; MEP; HMBPP; β-carotene; IspG; IspH