1. Local metabolic response of Escherichia coli to the module genetic perturbations in l-methionine biosynthetic pathway.
- Author
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Shen, Zhen-Yang, Wang, Yi-Feng, Wang, Li-Juan, Wang, Ying, Liu, Zhi-Qiang, and Zheng, Yu-Guo
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METHIONINE , *ESCHERICHIA coli , *BIOSYNTHESIS , *CYSTEINE - Abstract
l -Methionine biosynthesis is through multilevel regulated and multibranched biosynthetic pathway (MRMBP). Because of the complex regulatory mechanism and the imbalanced metabolic flux between branched pathways, microbial production of l -methionine has not been commercialized. In this study, local metabolic response in MRMBP of l -methionine was investigated and various crucial genes in branched pathways were determined. In l -serine pathway, the crucial gene was serABC. In O -succinyl homoserine (OSH) pathway, which was the C4 backbone of l -methionine, metB and metL controlled the metabolic flux jointly. In l -cysteine pathway, the crucial gene cysE fbr could disturb the flux distribution of local network in l -methionine biosynthesis. However, no crucial gene for l -methionine production in 5-methyl tetrahydrofolate (CH 3 -THF) pathway was found. The relation between these pathways was also researched. l -Serine pathway, as the upstream pathway of l -cysteine and CH 3 -THF, played a crucial role in l -methionine biosynthesis. l -Cysteine pathway showed the strongest controlling force of the metabolic flux, and OSH pathway was second to l -cysteine pathway. In contrast, CH 3 -THF pathway was the weakest, which was probably the mainly limited steps at present and had great potential in further research. In addition, constructed W3110 IJAHFEBC/pA∗HAmL was able to produce 2.62 g/L l -methionine in flask. This study is instructive for l -methionine biosynthesis and provides a new research method of biosynthesizing other metabolic products in MRMBPs. [Display omitted] • Multilevel regulated and multibranched biosynthetic pathways (MRMBPs) for l -methionine biosynthesis were analyzed. • Various crucial genes in MRMBPs for l -methionine biosynthesis were determined. • The balance between MRMBPs for l -methionine biosynthesis was clarified. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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