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Zhou J, Wang J, Yao M, He J, Yang Y, Li X, Tan Z, Shi H, Zhu X, Tian B. An acetate-independent pathway for isopropanol production via HMG-CoA in Escherichia coli. J Biotechnol 2022; 359:29-34. [PMID: 36150604 DOI: 10.1016/j.jbiotec.2022.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/09/2022] [Accepted: 09/18/2022] [Indexed: 11/17/2022]
Abstract
Isopropanol has a good potential as a new fuel substitution. In the model biosynthesis pathway of isopropanol synthesis, acetoacetyl-CoA is converted to acetoacetate by acetoacetyl-CoA transferases, which requires an acetate molecule as a substrate. Herein, a novel isopropanol synthesis pathway based on mammalian ketone metabolic pathway was developed. In this pathway, acetoacetyl-CoA is condensed with acetyl-CoA to generate 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) by HMG-CoA synthase, and then catalyzed by HMG-CoA lyase to generate acetoacetate. This process is acetate-independent. Under the same experimental system using glycerol as carbon source, the E. coli strain MG::ISOP1 containing the novel pathway produced 11.7 times more isopropanol than the strain MG::ISOP0 containing the model pathway. The pta-ackA knockout mutant strain MG∆pta-ackA::ISOP1, which reduced the conversion of acetyl-CoA to acetate, further increased the production from 76 mg/L to 360 mg/L. In another strategy, knocking out atoDA to block the acetoacetate degradation pathway in strain MG∆atoDA::ISOP1 increased the production to 680 mg/L. By knocking out both of pta-ackA and atoDA, strain MGΔpta-ackAΔatoDA::ISOP1 produced 964 mg/L of isopropanol, which was 12.7 times that of MG::ISOP1. This study indicated that the novel pathway is competent for isopropanol synthesis, and provides a new perspective for biosynthesis of isopropanol.
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Affiliation(s)
- Jia Zhou
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Jiahui Wang
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Mengdie Yao
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Junyi He
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Yuxiang Yang
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China
| | - Xiangqian Li
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China
| | - Zhongbiao Tan
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Hao Shi
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Xiaoyan Zhu
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - Baoxia Tian
- Faculty of Life Science and Food Engineering, HuaiYin Institute of Technology, Huaian 223003, PR China; Jiangsu Provincial Engineering Laboratory for Biomass Conversion and Process Integration, Huaiyin Institute of Technology, Huaian 223003, PR China.
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Fu Z, Runquist JA, Montgomery C, Miziorko HM, Kim JJP. Functional insights into human HMG-CoA lyase from structures of Acyl-CoA-containing ternary complexes. J Biol Chem 2010; 285:26341-9. [PMID: 20558737 DOI: 10.1074/jbc.m110.139931] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HMG-CoA lyase (HMGCL) is crucial to ketogenesis, and inherited human mutations are potentially lethal. Detailed understanding of the HMGCL reaction mechanism and the molecular basis for correlating human mutations with enzyme deficiency have been limited by the lack of structural information for enzyme liganded to an acyl-CoA substrate or inhibitor. Crystal structures of ternary complexes of WT HMGCL with the competitive inhibitor 3-hydroxyglutaryl-CoA and of the catalytically deficient HMGCL R41M mutant with substrate HMG-CoA have been determined to 2.4 and 2.2 A, respectively. Comparison of these beta/alpha-barrel structures with those of unliganded HMGCL and R41M reveals substantial differences for Mg(2+) coordination and positioning of the flexible loop containing the conserved HMGCL "signature" sequence. In the R41M-Mg(2+)-substrate ternary complex, loop residue Cys(266) (implicated in active-site function by mechanistic and mutagenesis observations) is more closely juxtaposed to the catalytic site than in the case of unliganded enzyme or the WT enzyme-Mg(2+)-3-hydroxyglutaryl-CoA inhibitor complex. In both ternary complexes, the S-stereoisomer of substrate or inhibitor is specifically bound, in accord with the observed Mg(2+) liganding of both C3 hydroxyl and C5 carboxyl oxygens. In addition to His(233) and His(235) imidazoles, other Mg(2+) ligands are the Asp(42) carboxyl oxygen and an ordered water molecule. This water, positioned between Asp(42) and the C3 hydroxyl of bound substrate/inhibitor, may function as a proton shuttle. The observed interaction of Arg(41) with the acyl-CoA C1 carbonyl oxygen explains the effects of Arg(41) mutation on reaction product enolization and explains why human Arg(41) mutations cause drastic enzyme deficiency.
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Affiliation(s)
- Zhuji Fu
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Chávez-Avilés M, Díaz-Pérez AL, Reyes-de la Cruz H, Campos-García J. The Pseudomonas aeruginosa liuE gene encodes the 3-hydroxy-3-methylglutaryl coenzyme A lyase, involved in leucine and acyclic terpene catabolism. FEMS Microbiol Lett 2009; 296:117-23. [PMID: 19459965 DOI: 10.1111/j.1574-6968.2009.01624.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The enzymes involved in the catabolism of leucine are encoded by the liu gene cluster in Pseudomonas aeruginosa PAO1. A mutant in the liuE gene (ORF PA2011) of P. aeruginosa was unable to utilize both leucine/isovalerate and acyclic terpenes as the carbon source. The liuE mutant grown in culture medium with citronellol accumulated metabolites of the acyclic terpene pathway, suggesting an involvement of liuE in both leucine/isovalerate and acyclic terpene catabolic pathways. The LiuE protein was expressed as a His-tagged recombinant polypeptide purified by affinity chromatography in Escherichia coli. LiuE showed a mass of 33 kDa under denaturing and 79 kDa under nondenaturing conditions. Protein sequence alignment and fingerprint sequencing suggested that liuE encodes 3-hydroxy-3-methylglutaryl-coenzyme A lyase (HMG-CoA lyase), which catalyzes the cleavage of HMG-CoA to acetyl-CoA and acetoacetate. LiuE showed HMG-CoA lyase optimal activity at a pH of 7.0 and 37 degrees C, an apparent K(m) of 100 microM for HMG-CoA and a V(max) of 21 micromol min(-1) mg(-1). These results demonstrate that the liuE gene of P. aeruginosa encodes for the HMG-CoA lyase, an essential enzyme for growth in both leucine and acyclic terpenes.
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Affiliation(s)
- Mauricio Chávez-Avilés
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
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Metzler DE, Metzler CM, Sauke DJ. Enzymatic Addition, Elimination, Condensation, and Isomerization. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50016-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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