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Improving the L-tyrosine production with application of repeated batch fermentation technology based on a novel centrifuge bioreactor. FOOD AND BIOPRODUCTS PROCESSING 2021. [DOI: 10.1016/j.fbp.2020.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tanaka N, Kanazawa M, Tonosaki K, Yokoyama N, Kuzuyama T, Takahashi Y. Novel features of the ISC machinery revealed by characterization of Escherichia coli mutants that survive without iron-sulfur clusters. Mol Microbiol 2015; 99:835-48. [PMID: 26560204 DOI: 10.1111/mmi.13271] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2015] [Indexed: 01/09/2023]
Abstract
Biological assembly of iron-sulfur (Fe-S) clusters is mediated by complex systems consisting of multiple proteins. Escherichia coli possesses two distinct systems called the ISC and SUF machineries encoded by iscSUA-hscBA-fdx-iscX and sufABCDSE respectively. Deletion of both pathways results in absence of the biosynthetic apparatus for Fe-S clusters, and consequent lethality, which has hampered detailed genetic studies. Here we report that modification of the isoprenoid biosynthetic pathway can offset the indispensability of the Fe-S cluster biosynthetic systems and show that the resulting Δisc Δsuf double mutants can grow without detectable Fe-S cluster-containing proteins. We also constructed a series of mutants in which each isc gene was disrupted in the deletion background of sufABCDSE. Phenotypic analysis of the mutants revealed that Fdx, an essential electron-transfer Fe-S protein in the ISC machinery, is dispensable under anaerobic conditions, which is similar to the situation with IscA. Furthermore, we found that several suppressor mutations in IscU, an Fe-S scaffold protein responsible for the de novo Fe-S cluster assembly, could bypass the essential role of the chaperone system HscA and HscB. These findings pave the way toward a detailed molecular analysis to understand the mechanisms involved in Fe-S cluster biosynthesis.
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Affiliation(s)
- Naoyuki Tanaka
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Miaki Kanazawa
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Keitaro Tonosaki
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Nao Yokoyama
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Tomohisa Kuzuyama
- Biotechnology Research Center, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yasuhiro Takahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
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