Mutation Analysis of the Feedback Inhibition Site of Aspartokinase III of Escherichia coli K-12 and its Use in L-Threonine Production.
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- OGAWA-MIYATA Yuri
- Fermentation & Biotechnology Laboratories, Ajinomoto Co. Inc.
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- KOJIMA Hiroyuki
- Fermentation & Biotechnology Laboratories, Ajinomoto Co. Inc.
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- SANO Konosuke
- Fermentation & Biotechnology Laboratories, Ajinomoto Co. Inc.
Bibliographic Information
- Other Title
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- Mutation Analysis of the Feedback Inhibition Site of Aspartokinase 3 of Escherichia coli K-12 and its Use in L-Threonine Production
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Abstract
Aspartokinase III (AKIII), one of three isozymes of Escherichia coli K-12, is inhibited allosterically by L-lysine. This enzyme is encoded by the lysC gene and has 449 amino acid residues. We analyzed the feedback inhibition site of AKIII by generating various lysC mutants in a plasmid vector. These mutants conferred resistance to L-lysine and/or an L-lysine analogue on their host.The inhibitory effects of L-lysine on and heat tolerance of 14 mutant enzymes were examined and DNA sequencing showed that the types of mutants were 12. Two hot spots, amino acid residue positions 318-325 and 345-352, were detected in the C-terminal region of AKIII and these enzyme regions may be important in L-lysine-mediated feedback inhibition of AKIII. Feedback resistant lysC relieved on L-threonine hyper-producing strain, B-3996, from reduced L-threonine productivity by addition of L-lysine, and furthermore increased L-threonin productivity even when no addition of L-lysine. It suggested that the bottleneck of L-threonine production of B-3996 was AK and feedback resistant lysC was effective because of the strict inhibition by cytoplasmic L-lysine.
Journal
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- Bioscience, Biotechnology, and Biochemistry
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Bioscience, Biotechnology, and Biochemistry 65 (5), 1149-1154, 2001
Japan Society for Bioscience, Biotechnology, and Agrochemistry
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Details 詳細情報について
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- CRID
- 1390001206476184704
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- NII Article ID
- 110002680406
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- NII Book ID
- AA10824164
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- COI
- 1:CAS:528:DC%2BD3MXktFaisLc%3D
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- ISSN
- 13476947
- 09168451
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- NDL BIB ID
- 5782719
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- PubMed
- 11440130
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- PubMed
- CiNii Articles
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- Abstract License Flag
- Disallowed