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Published on: January 13, 2017
[Corynebacterium pekinense transketolase: gene cloning, sequence analysis and expression].
Weike Ji1, Zhi Zhao, Yingzi Zhang
1Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China. jiwk@im.ac.cn
Wei Sheng Wu Xue Bao = Acta Microbiologica Sinica
|January 29, 2011
Summary
Cloning the transketolase (TK) gene from Corynebacterium pekinense and expressing it in a mutant strain enhanced L-tryptophan production. This increase in TK activity did not negatively impact cell growth, offering a promising metabolic engineering strategy.
Area of Science:
- Microbial biotechnology
- Enzyme engineering
- Metabolic pathway analysis
Context:
- The non-oxidative pentose phosphate pathway is crucial for cellular biosynthesis.
- Transketolase (TK) is a key regulatory enzyme in this pathway.
- Understanding TK gene expression in Corynebacterium pekinense is vital for optimizing metabolic processes.
Purpose:
- To clone the transketolase (tkt) gene from Corynebacterium pekinense wild-type and mutant strains.
- To investigate the effect of tkt gene expression on the physiological characteristics of C. pekinense.
- To enhance L-tryptophan production through genetic manipulation.
Summary:
- The tkt gene was successfully cloned from Corynebacterium pekinense AS 1.299 and its mutant PD-67.
- Sequence analysis revealed no base changes in the tkt gene between the wild-type and mutant strains, but identified five amino acid changes compared to Corynebacterium glutamicum ATCC 13032, with four affecting thiamine pyrophosphate binding sites.
- Recombinant expression of the tkt gene in C. pekinense PD-67 resulted in a two-fold increase in TK specific enzyme activity, leading to higher cell mass and increased L-tryptophan accumulation.
Impact:
- Moderate amplification of TK activity enhances L-tryptophan production.
- Increased TK activity does not adversely affect cell growth.
- This study provides a foundation for metabolic engineering strategies to improve amino acid production in C. pekinense.
