Molecular and cellular research on aromatic amino acids production, by microorganisms.

微生物生产芳香氨基酸的分子和细胞研究。

• 批准号: 14360056
• 负责人: KUMAGAI Hidehiko
• 金额: $ 11.01万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14360056/
• 关键词: Tyrosine phenol lyase; TyrR; DOPA; Erwinia herbicola; tutB; LIVI; LS system; transporter; aromatic amino acids; TutB; LIV-I; DOPA; Ervinia herbicola; Erwinia harbicola; 転写調節

In Escherichia coli, the active transport of phenylalanine is considered to be performed by two different systems, AroP and PheP However, a low. level of accumulation of phenylalanine was observed in an aromatic amino acid transporter-deficient E. coli strain (ΔaroP ΔpheP Δmtr Δtna ΔtyrP). The uptake of phenylalanine by this strain was significantly inhibited in the presence of branched-chain amino acids. Genetic analysis and transport studies revealed that the LIV-I/LS system, which is a branched-chain amino acid transporter consisting of two periplasmic binding proteins, the LIV-binding protein (LIV-I system) and LS-binding protein (LS system), and membrane components, LivHMGF, is involved in phenylalanine accumulation.in. E. coli. cells. The Km values for phenylalanine in the-LIV-I and LS systems were determined to be 19 and 30 μM, respectively. Competitive inhibition of phenylalanine uptake by isoleucine, leucine, and valine was observed for the LIV-I system and, surprisingly, also for the LS system, which has been assumed to be leucine specific on the basis of the results of binding studies with the purified LS-binding protein. We found that the LS system is capable of transporting isoleucine and valine with affinity comparable to that far leucine and that the LIV-I system is able to transport tyrosine with affinity lower than that seen with other substrates. The physiological importance of the LIV-I/LS system for phenylalanine accumulation was revealed in the growth of phenylalanine-auxotrophic E. coli strains under various conditions.

在大肠杆菌中，苯丙氨酸的主动转运被认为是由两个不同的系统执行的，AROP和PheP，然而，一个低。在一株芳香氨基酸转运蛋白缺陷型大肠杆菌(ΔaropΔphePΔmtrΔtnaΔtyrP)中观察到苯丙氨酸的积累水平。在支链氨基酸存在的情况下，该菌株对苯丙氨酸的吸收受到显著抑制。遗传分析和转运研究表明，Liv-I/LS系统是由两个周质结合蛋白Liv结合蛋白(Liv-I系统)和LS结合蛋白(LS系统)以及膜组分LivHMGF组成的支链氨基酸转运体，参与苯丙氨酸的积累。大肠埃希菌。细胞。测得苯丙氨酸在LiV-I和LS体系中的Km值分别为19和30μM。异亮氨酸、亮氨酸和缬氨酸对苯丙氨酸摄取的竞争性抑制在Liv-I系统中观察到，令人惊讶的是，也在LS系统中观察到，根据与纯化的LS结合蛋白的结合研究结果，该系统被认为是亮氨酸专一性的。我们发现LS系统能够以与远端亮氨酸相当的亲和力转运异亮氨酸和缬氨酸，而LiV-I系统能够以比其他底物更低的亲和力转运酪氨酸。在不同条件下，LIV-I/LS系统对苯丙氨酸营养缺陷型大肠杆菌菌株的生长具有重要的生理意义。

项目成果

T.katayama, H.Suzuki, T.Koyanagi, H.Kumagai: "Functional analysis of the Erwinia herbicola tutB gene and its product"Journal of Bacteriology. 184(11). 3135-3141 (2002)

T.katayama、H.Suzuki、T.Koyanagi、H.Kumagai：“草欧文氏菌 tutB 基因及其产物的功能分析”细菌学杂志。

T.Katayama et al.: "Functional analysis of the Erwinia herbicola tutB gene and its product."Journal of Bacteriology. 184(11). 3135-3141 (2002)

T.Katayama 等人：“草欧文氏菌 tutB 基因及其产物的功能分析。”细菌学杂志。

T.Katayama, T.Koyanagi, H.Suzuki, H.Kumagai.: "Expression of tyrosine phenol lyase which is used for L-DOPA production. The regulation of its expression and over-expression by its mutant regulators."Ouyou Biseibutsugaku Kennkyu. 1(2). 130-137 (2003)

T.Katayama、T.Koyanagi、H.Suzuki、H.Kumagai.：“用于 L-DOPA 生产的酪氨酸苯酚裂合酶的表达。其突变调节剂对其表达和过度表达的调节。”Ouyou Biseibutsugaku Kennkyu

T.Koyanagi et al.: "Identification of the LIV-I/LS system as the third phenylalanine transporter in Escherichia coli K-12"Journal of Bacteriology. 186(2). 343-350 (2004)

T.Koyanagi 等人：“LIV-I/LS 系统作为大肠杆菌 K-12 中第三个苯丙氨酸转运蛋白的鉴定”细菌学杂志。

T.Koyanagi et al.: "Identification of the LIV-I/LS system as the third phenylalanine transporter in Escherichia coli K-12."Journal of Bacteriology. 186(2). 343-350 (2004)

T.Koyanagi 等人：“LIV-I/LS 系统作为大肠杆菌 K-12 中第三种苯丙氨酸转运蛋白的鉴定。”细菌学杂志。