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Miyamoto T, Kobayashi F, Emori K, Sakai-Kato K. Multifunctionality of a low-specificity L-threonine aldolase from the hyperthermophile Thermotoga maritima. Extremophiles 2024; 28:41. [PMID: 39192163 DOI: 10.1007/s00792-024-01357-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Accepted: 08/20/2024] [Indexed: 08/29/2024]
Abstract
The peptidoglycan of the hyperthermophile Thermotoga maritima contains an unusual D-lysine in addition to the typical D-alanine and D-glutamate. Previously, we identified the D-lysine and D-glutamate biosynthetic pathways of T. maritima. Additionally, we reported some multifunctional enzymes involved in amino acid metabolism. In the present study, we characterized the enzymatic properties of TM1744 (threonine aldolase) to probe both its potential multifunctionality and D-amino acid metabolizing activities. TM1744 displayed aldolase activity toward both L-allo-threonine and L-threonine, and exhibited higher activity toward L-threo-phenylserine. It did not function as an aldolase toward D-allo-threonine or D-threonine. Furthermore, TM1744 had racemase activity toward two amino acids, although its racemase activity was lower than its aldolase activity. TM1744 did not have other amino acid metabolizing activities. Therefore, TM1744 is a low-specificity L-threonine aldolase with limited racemase activity.
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Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan.
- School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan.
| | - Fugo Kobayashi
- School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan
| | - Konan Emori
- School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan
| | - Kumiko Sakai-Kato
- Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan
- School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan
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2
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Miyamoto T. Multifunctional enzymes related to amino acid metabolism in bacteria. Biosci Biotechnol Biochem 2024; 88:585-593. [PMID: 38439669 DOI: 10.1093/bbb/zbae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/29/2024] [Indexed: 03/06/2024]
Abstract
In bacteria, d-amino acids are primarily synthesized from l-amino acids by amino acid racemases, but some bacteria use d-amino acid aminotransferases to synthesize d-amino acids. d-Amino acids are peptidoglycan components in the cell wall involved in several physiological processes, such as bacterial growth, biofilm dispersal, and peptidoglycan metabolism. Therefore, their metabolism and physiological roles have attracted increasing attention. Recently, we identified novel bacterial d-amino acid metabolic pathways, which involve amino acid racemases, with broad substrate specificity, as well as multifunctional enzymes with d-amino acid-metabolizing activity. Here, I review these multifunctional enzymes and their related d- and l-amino acid metabolic pathways in Escherichia coli and the hyperthermophile Thermotoga maritima.
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Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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3
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Brytan W, Shortall K, Duarte F, Soulimane T, Padrela L. Contribution of a C-Terminal Extension to the Substrate Affinity and Oligomeric Stability of Aldehyde Dehydrogenase from Thermus thermophilus HB27. Biochemistry 2024; 63:1075-1088. [PMID: 38602394 PMCID: PMC11080044 DOI: 10.1021/acs.biochem.3c00698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/12/2024]
Abstract
Aldehyde dehydrogenase enzymes (ALDHs) are widely studied for their roles in disease propagation and cell metabolism. Their use in biocatalysis applications, for the conversion of aldehydes to carboxylic acids, has also been recognized. Understanding the structural features and functions of both prokaryotic and eukaryotic ALDHs is key to uncovering novel applications of the enzyme and probing its role in disease propagation. The thermostable enzyme ALDHTt originating fromThermus thermophilus, strain HB27, possesses a unique extension of its C-terminus, which has been evolutionarily excluded from mesophilic counterparts and other thermophilic enzymes in the same genus. In this work, the thermophilic adaptation is studied by the expression and optimized purification of mutant ALDHTt-508, with a 22-amino acid truncation of the C-terminus. The mutant shows increased activity throughout production compared to native ALDHTt, indicating an opening of the active site upon C-terminus truncation and giving rationale into the evolutionary exclusion of the C-terminal extension from similar thermophilic and mesophilic ALDH proteins. Additionally, the C-terminus is shown to play a role in controlling substrate specificity of native ALDH, particularly in excluding catalysis of certain large and certain aromatic ortho-substituted aldehydes, as well as modulating the protein's pH tolerance by increasing surface charge. Dynamic light scattering and size-exclusion HPLC methods are used to show the role of the C-terminus in ALDHTt oligomeric stability at the cost of catalytic efficiency. Studying the aggregation rate of ALDHTt with and without a C-terminal extension leads to the conclusion that ALDHTt follows a monomolecular reaction aggregation mechanism.
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Affiliation(s)
- Wiktoria Brytan
- Department
of Chemical Sciences, Bernal Institute,
University of Limerick, Limerick V94 T9PX, Ireland
| | - Kim Shortall
- Department
of Chemical Sciences, Bernal Institute,
University of Limerick, Limerick V94 T9PX, Ireland
| | - Francisco Duarte
- Department
of Chemical Sciences, Bernal Institute,
University of Limerick, Limerick V94 T9PX, Ireland
| | - Tewfik Soulimane
- Department
of Chemical Sciences, Bernal Institute,
University of Limerick, Limerick V94 T9PX, Ireland
- SSPC
− The Science Foundation Ireland Research Centre for Pharmaceuticals, Limerick V94 T9PX,Ireland
| | - Luis Padrela
- Department
of Chemical Sciences, Bernal Institute,
University of Limerick, Limerick V94 T9PX, Ireland
- SSPC
− The Science Foundation Ireland Research Centre for Pharmaceuticals, Limerick V94 T9PX,Ireland
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Miyamoto T, Saitoh Y, Katane M, Sekine M, Homma H. YgeA is involved in L- and D-homoserine metabolism in Escherichia coli. FEMS Microbiol Lett 2022; 369:6754731. [PMID: 36214408 DOI: 10.1093/femsle/fnac096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 08/06/2022] [Accepted: 10/07/2022] [Indexed: 12/13/2022] Open
Abstract
Noncanonical D-amino acids are involved in peptidoglycan and biofilm metabolism in bacteria. Previously, we identified amino acid racemases with broad substrate specificity, including YgeA from Escherichia coli, which strongly prefers homoserine as a substrate. In this study, we investigated the functions of this enzyme in vivo. When wild-type and ygeA-deficient E. coli strains were cultured in minimal medium containing D-homoserine, the D-homoserine level was significantly higher in the ygeA-deficient strain than in the wild-type strain, in which it was almost undetectable. Additionally, D-homoserine was detected in YgeA-expressed E. coli cells cultured in minimal medium containing L-homoserine. The growth of the ygeA-deficient strain was significantly impaired in minimal medium with or without supplemental D-homoserine, while L-methionine, L-threonine or L-isoleucine, which are produced via L-homoserine, restored the growth impairment. Furthermore, the wild-type strain formed biofilms significantly more efficiently than the ygeA-deficient strain. Addition of L- or D-homoserine significantly suppressed biofilm formation in the wild-type strain, whereas this addition had no significant effect in the ygeA-deficient strain. Together, these data suggest that YgeA acts as an amino acid racemase and plays a role in L- and D-homoserine metabolism in E. coli.
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Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
| | - Yasuaki Saitoh
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
| | - Masumi Katane
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
| | - Masae Sekine
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
| | - Hiroshi Homma
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
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Miyamoto T, Moriya T, Katane M, Saitoh Y, Sekine M, Sakai‐Kato K, Oshima T, Homma H. Identification of a novel
d
‐amino acid aminotransferase involved in
d
‐glutamate biosynthetic pathways in the hyperthermophile
Thermotoga maritima. FEBS J 2022; 289:5933-5946. [DOI: 10.1111/febs.16452] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 03/22/2022] [Accepted: 04/01/2022] [Indexed: 02/02/2023]
Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences Kitasato University Tokyo Japan
| | - Toshiyuki Moriya
- Institute of Environmental Microbiology Kyowa Kako Co. Tokyo Japan
| | - Masumi Katane
- Graduate School of Pharmaceutical Sciences Kitasato University Tokyo Japan
| | - Yasuaki Saitoh
- Graduate School of Pharmaceutical Sciences Kitasato University Tokyo Japan
| | - Masae Sekine
- Graduate School of Pharmaceutical Sciences Kitasato University Tokyo Japan
| | - Kumiko Sakai‐Kato
- Graduate School of Pharmaceutical Sciences Kitasato University Tokyo Japan
| | - Tairo Oshima
- Institute of Environmental Microbiology Kyowa Kako Co. Tokyo Japan
| | - Hiroshi Homma
- Graduate School of Pharmaceutical Sciences Kitasato University Tokyo Japan
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Study of ALDH from Thermus thermophilus-Expression, Purification and Characterisation of the Non-Substrate Specific, Thermophilic Enzyme Displaying Both Dehydrogenase and Esterase Activity. Cells 2021; 10:cells10123535. [PMID: 34944041 PMCID: PMC8699947 DOI: 10.3390/cells10123535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 01/16/2023] Open
Abstract
Aldehyde dehydrogenases (ALDH), found in all kingdoms of life, form a superfamily of enzymes that primarily catalyse the oxidation of aldehydes to form carboxylic acid products, while utilising the cofactor NAD(P)+. Some superfamily members can also act as esterases using p-nitrophenyl esters as substrates. The ALDHTt from Thermus thermophilus was recombinantly expressed in E. coli and purified to obtain high yields (approximately 15–20 mg/L) and purity utilising an efficient heat treatment step coupled with IMAC and gel filtration chromatography. The use of the heat treatment step proved critical, in its absence decreased yield of 40% was observed. Characterisation of the thermophilic ALDHTt led to optimum enzymatic working conditions of 50 °C, and a pH of 8. ALDHTt possesses dual enzymatic activity, with the ability to act as a dehydrogenase and an esterase. ALDHTt possesses broad substrate specificity, displaying activity for a range of aldehydes, most notably hexanal and the synthetic dialdehyde, terephthalaldehyde. Interestingly, para-substituted benzaldehydes could be processed efficiently, but ortho-substitution resulted in no catalytic activity. Similarly, ALDHTt displayed activity for two different esterase substrates, p-nitrophenyl acetate and p-nitrophenyl butyrate, but with activities of 22.9% and 8.9%, respectively, compared to the activity towards hexanal.
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Miyamoto T, Saitoh Y, Katane M, Sekine M, Sakai-Kato K, Homma H. Acetylornithine aminotransferase TM1785 performs multiple functions in the hyperthermophile Thermotoga maritima. FEBS Lett 2021; 595:2931-2941. [PMID: 34747014 DOI: 10.1002/1873-3468.14222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/29/2021] [Accepted: 10/31/2021] [Indexed: 02/02/2023]
Abstract
The hyperthermophilic bacterium Thermotoga maritima peptidoglycan contains unusual d-lysine alongside typical d-alanine and d-glutamate. We previously identified lysine racemase and threonine dehydratase, but knowledge of d-amino acid metabolism remains limited. Herein, we identified and characterized T. maritima acetylornithine aminotransferase TM1785. The enzyme was most active towards acetyl-l-ornithine, but also utilized l-glutamate, l-ornithine and acetyl-l-lysine as amino donors, and 2-oxoglutarate was the preferred amino acceptor. TM1785 also displayed racemase activity towards four amino acids and lyase activity towards l-cysteine, but no dehydratase activity towards l-serine, l-threonine or corresponding d-amino acids. Catalytic efficiency (kcat /Km ) was highest for aminotransferase activity and lowest for racemase activity. TM1785 is a novel acetylornithine aminotransferase associated with l-arginine biosynthesis that possesses two additional distinct activities.
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Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Yasuaki Saitoh
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Masumi Katane
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Masae Sekine
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Kumiko Sakai-Kato
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Hiroshi Homma
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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Abstract
Like many biological compounds, proteins are found primarily in their homochiral form. However, homochirality is not guaranteed throughout life. Determining their chiral proteinogenic sequence is a complex analytical challenge. This is because certain d-amino acids contained in proteins play a role in human health and disease. This is the case, for example, with d-Asp in elastin, β-amyloid and α-crystallin which, respectively, have an action on arteriosclerosis, Alzheimer’s disease and cataracts. Sequence-dependent and sequence-independent are the two strategies for detecting the presence and position of d-amino acids in proteins. These methods rely on enzymatic digestion by a site-specific enzyme and acid hydrolysis in a deuterium or tritium environment to limit the natural racemization of amino acids. In this review, chromatographic and electrophoretic techniques, such as LC, SFC, GC and CE, will be recently developed (2018–2020) for the enantioseparation of amino acids and peptides. For future work, the discovery and development of new chiral stationary phases and derivatization reagents could increase the resolution of chiral separations.
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Identification and biochemical characterization of threonine dehydratase from the hyperthermophile Thermotoga maritima. Amino Acids 2021; 53:903-915. [PMID: 33938999 DOI: 10.1007/s00726-021-02993-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/21/2021] [Indexed: 01/14/2023]
Abstract
The peptidoglycan of the hyperthermophile Thermotoga maritima contains an unusual component, D-lysine (D-Lys), in addition to the typical D-alanine (D-Ala) and D-glutamate (D-Glu). In a previous study, we identified a Lys racemase that is presumably associated with D-Lys biosynthesis. However, our understanding of D-amino acid metabolism in T. maritima and other bacteria remains limited, although D-amino acids in the peptidoglycan are crucial for preserving bacterial cell structure and resistance to environmental threats. Herein, we characterized enzymatic and structural properties of TM0356 that shares a high amino acid sequence identity with serine (Ser) racemase. The results revealed that TM0356 forms a tetramer with each subunit containing a pyridoxal 5'-phosphate as a cofactor. The enzyme did not exhibit racemase activity toward various amino acids including Ser, and dehydratase activity was highest toward L-threonine (L-Thr). It also acted on L-Ser and L-allo-Thr, but not on the corresponding D-amino acids. The catalytic mechanism did not follow typical Michaelis-Menten kinetics; it displayed a sigmoidal dependence on substrate concentration, with highest catalytic efficiency (kcat/K0.5) toward L-Thr. Interestingly, dehydratase activity was insensitive to allosteric regulators L-valine and L-isoleucine (L-Ile) at low concentrations, while these L-amino acids are inhibitors at high concentrations. Thus, TM0356 is a biosynthetic Thr dehydratase responsible for the conversion of L-Thr to α-ketobutyrate and ammonia, which is presumably involved in the first step of the biosynthesis of L-Ile.
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Miyamoto T, Homma H, Miyamoto T. D-Amino acid metabolism in bacteria. J Biochem 2021; 170:5-13. [PMID: 33788945 DOI: 10.1093/jb/mvab043] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 03/19/2021] [Indexed: 02/02/2023] Open
Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Hiroshi Homma
- Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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