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Zhu C, Cheng Y, Shi Q, Ge X, Yang Y, Huang Y. Metagenomic analyses reveal microbial communities and functional differences between Daqu from seven provinces. Food Res Int 2023; 172:113076. [PMID: 37689857 DOI: 10.1016/j.foodres.2023.113076] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 04/28/2023] [Accepted: 05/29/2023] [Indexed: 09/11/2023]
Abstract
Microbial communities perform the brewing function in Daqu. Macrogenomics and PICRUST II analyses revealed the differences in microbes and metabolic functions among Daqu from the seven Baijiu-producing provinces. Jiang-flavored Daqu (Guizhou, Shandong, and Hubei provinces) generally forms an aroma-producing functional microbiota with Kroppenstedtia, Bacillus, Thermoascus, Virgibacillus, and Thermomyces as the core, which promotes the metabolism of various amino acids and aroma compounds. Light-flavored Daqu (Shanxi Province) enriched the Saccharomycopsis, Saccharomyces, and lactic acid bacteria (LAB) microbiota through low-temperature fermentation. These microbes can synthesize alcohol and lactic acid but inhibit amino acid metabolism within the Light-flavored Daqu. Bifidobacterium and Saccharomycopsis were dominant in the Tao-flavored Daqu (Henan province). This unique microbial structure is beneficial for pyruvate fermentation to lactate. Research also found that Strong-flavored Daqu from Jiangsu and Sichuan provinces differed significantly. The microbial communities and metabolic pathways within Jiangsu Daqu were similar to those within Jiang-flavored Daqu, but Sichuan Daqu was dominated by Thermoascus, LAB, and Thermoactinomyces. In addition, Spearman correlation analysis indicated that Kroppenstedtia, Bacillus, and Thermomyces were not only positively related to flavor metabolism but also negatively correlated with Saccharomycopsis. This research will help establish a systematic understanding of the microbial community and functional characteristics in Daqu.
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Affiliation(s)
- Chutian Zhu
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, China
| | - Yuxin Cheng
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025, China
| | - Qili Shi
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025, China
| | - Xiangyang Ge
- Yanghe Distillery Co., Ltd., Suqian, Jiangsu 223800, China
| | - Yong Yang
- Yanghe Distillery Co., Ltd., Suqian, Jiangsu 223800, China
| | - Yongguang Huang
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025, China; Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, China
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2
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Li J, Li H, Liu H, Luo Y. Recent Advances in the Biosynthesis of Natural Sugar Substitutes in Yeast. J Fungi (Basel) 2023; 9:907. [PMID: 37755015 PMCID: PMC10533046 DOI: 10.3390/jof9090907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/29/2023] [Accepted: 09/01/2023] [Indexed: 09/28/2023] Open
Abstract
Natural sugar substitutes are safe, stable, and nearly calorie-free. Thus, they are gradually replacing the traditional high-calorie and artificial sweeteners in the food industry. Currently, the majority of natural sugar substitutes are extracted from plants, which often requires high levels of energy and causes environmental pollution. Recently, biosynthesis via engineered microbial cell factories has emerged as a green alternative for producing natural sugar substitutes. In this review, recent advances in the biosynthesis of natural sugar substitutes in yeasts are summarized. The metabolic engineering approaches reported for the biosynthesis of oligosaccharides, sugar alcohols, glycosides, and rare monosaccharides in various yeast strains are described. Meanwhile, some unresolved challenges in the bioproduction of natural sugar substitutes in yeast are discussed to offer guidance for future engineering.
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Affiliation(s)
- Jian Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (J.L.); (H.L.); (H.L.)
| | - Honghao Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (J.L.); (H.L.); (H.L.)
| | - Huayi Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (J.L.); (H.L.); (H.L.)
| | - Yunzi Luo
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; (J.L.); (H.L.); (H.L.)
- Georgia Tech Shenzhen Institute, Tianjin University, Tangxing Road 133, Nanshan District, Shenzhen 518071, China
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3
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Yoon Y, Park H, An S, Ahn JH, Kim B, Shin J, Kim YE, Yeon J, Chung JH, Kim D, Cho M. Bacterial degradation kinetics of poly(Ɛ-caprolactone) (PCL) film by Aquabacterium sp. CY2-9 isolated from plastic-contaminated landfill. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 335:117493. [PMID: 36822047 DOI: 10.1016/j.jenvman.2023.117493] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/27/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Despite the identification of numerous bioplastic-degrading bacteria, the inconsistent rate of bioplastic degradation under differing cultivation conditions limits the intercomparison of results on biodegradation kinetics. In this study, we isolated a poly (Ɛ-caprolactone) (PCL)-degrading bacterium from a plastic-contaminated landfill and determined the principle-based biodegradation kinetics in a confined model system of varying cultivation conditions. Bacterial degradation of PCL films synthesized by different polymer number average molecular weights (Mn) and concentrations (% w/v) was investigated using both solid and liquid media at various temperatures. As a result, the most active gram-negative bacterial strain at ambient temperature (28 °C), designated CY2-9, was identified as Aquabacterium sp. Based on 16 S rRNA gene analysis. A clear zone around the bacterial colony was apparently exhibited during solid cultivation, and the diameter sizes increased with incubation time. During biodegradation processes in the PCL film, the thermal stability declined (determined by TGA; weight changes at critical temperature), whereas the crystalline proportion increased (determined by DSC; phase transition with temperature increment), implying preferential degradation of the amorphous region in the polymer structure. The surface morphologies (determined by SEM; electron optical system) were gradually hydrolyzed, creating destruction patterns as well as alterations in functional groups on film surfaces (determined by FT-IR; infrared spectrum of absorption or emission). In the kinetic study based on the weight loss of the PCL film (4.5 × 104 Da, 1% w/v), ∼1.5 (>±0.1) × 10-1 day-1 was obtained from linear regression for both solid and liquid media cultivation at 28 °C. The biodegradation efficiencies increased proportionally by a factor of 2.6-7.9, depending on the lower polymer number average molecular weight and lower concentration. Overall, our results are useful for measuring and/or predicting the degradation rates of PCL films by microorganisms in natural environments.
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Affiliation(s)
- Younggun Yoon
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea; Division of Biotechnology, SELS Center, College of Environmental and Bioresource Sciences, Jeonbuk National University, Iksan, Jeonbuk, 54596, South Korea.
| | - Hyojung Park
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Sihyun An
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Jae-Hyung Ahn
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Bongkyu Kim
- Division of Biotechnology, SELS Center, College of Environmental and Bioresource Sciences, Jeonbuk National University, Iksan, Jeonbuk, 54596, South Korea
| | - Jaedon Shin
- Department of Environmental Engineering, Kunsan National University, Gunsan, 54150, Republic of Korea
| | - Ye-Eun Kim
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Jehyeong Yeon
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Joon-Hui Chung
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Dayeon Kim
- Agricultural Microbiology Division, National Institute of Agricultural Sciences, 166 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 55365, Republic of Korea
| | - Min Cho
- Division of Biotechnology, SELS Center, College of Environmental and Bioresource Sciences, Jeonbuk National University, Iksan, Jeonbuk, 54596, South Korea
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Andersen S, Nawrocki A, Johansen AE, Herrero-Fresno A, Menéndez VG, Møller-Jensen J, Olsen JE. Proteomes of Uropathogenic Escherichia coli Growing in Human Urine and in J82 Urinary Bladder Cells. Proteomes 2022; 10:proteomes10020015. [PMID: 35645373 PMCID: PMC9149909 DOI: 10.3390/proteomes10020015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/24/2022] [Accepted: 04/26/2022] [Indexed: 12/17/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) are the most common cause of urinary tract infection (UTI). UPEC normally reside in the intestine, and during establishment of UTI, they undergo metabolic adaptations, first to urine and then upon tissue invasion to the bladder cell interior. To understand these adaptations, we used quantitative proteomic profiling to characterize protein expression of the UPEC strain UTI89 growing in human urine and when inside J82 bladder cells. In order to facilitate detection of UPEC proteins over the excess amount of eukaryotic proteins in bladder cells, we developed a method where proteins from UTI89 grown in MOPS and urine was spiked-in to enhance detection of bacterial proteins. More than 2000 E. coli proteins were detected. During growth in urine, proteins associated with iron acquisition and several amino acid uptake and biosynthesis systems, most prominently arginine metabolism, were significantly upregulated. During growth in J82 cells, proteins related to iron uptake and arginine metabolisms were likewise upregulated together with proteins involved in sulfur compound turnover. Ribosomal proteins were downregulated relative to growth in MOPS in this environment. There was no direct correlation between upregulated proteins and proteins reported to be essential for infections, showing that upregulation during growth does not signify that the proteins are essential for growth under a condition.
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Affiliation(s)
- Sisse Andersen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark; (S.A.); (A.E.J.); (A.H.-F.); (V.G.M.)
| | - Arkadiusz Nawrocki
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark; (A.N.); (J.M.-J.)
| | - Andreas Eske Johansen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark; (S.A.); (A.E.J.); (A.H.-F.); (V.G.M.)
| | - Ana Herrero-Fresno
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark; (S.A.); (A.E.J.); (A.H.-F.); (V.G.M.)
| | - Vanesa García Menéndez
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark; (S.A.); (A.E.J.); (A.H.-F.); (V.G.M.)
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark; (A.N.); (J.M.-J.)
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark; (S.A.); (A.E.J.); (A.H.-F.); (V.G.M.)
- Correspondence:
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5
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Ni Z, Wu J, Li Z, Yuan L, Wang Y, Chen X, Yao J. Enhanced bioproduction of fucosylated oligosaccharide 3-fucosyllactose in engineered Escherichia coli with an improved de novo pathway. Biosci Biotechnol Biochem 2021; 85:1772-1781. [PMID: 33904902 DOI: 10.1093/bbb/zbab074] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 04/22/2021] [Indexed: 01/17/2023]
Abstract
3-fucosyllactose (3-FL) and 2'-fucosyllactose (2'-FL), are two important fucosylated oligosaccharides in human milk. Extensive studies on 2'-FL enabled its official approval for use in infant formula. However, development of 3-FL has been somewhat sluggish due to its low content in human milk and poor yield in enlarged production. Here, an α-1,3-fucosyltransferase mutant was introduced into an engineered Escherichia coli (E. coli) capable of producing GDP-L-fucose, leading to a promising 3-FL titer in a 5.0-L bioreactor. To increase the availability of cofactors (NADPH and GTP) for optimized 3-FL production, zwf, pntAB, and gsk genes were successively overexpressed, finally resulting in a higher 3-FL level with a titer of 35.72 g/L and a yield of 0.82 mol 3-FL/mol lactose. Unexpectedly, the deletion of pfkA gene led to a much lower performance of 3-FL production than the control strain. Still, our strategy achieved the highest 3-FL level in E. coli to date.
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Affiliation(s)
- Zhijian Ni
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, P. R. China.,Science Island Branch of Graduate School , University of Science & Technology of China, Hefei, P. R. China
| | - Jinyong Wu
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, P. R. China.,Huainan New Energy Research Center, Institute of Plasma Physics, Chinese Academy of Sciences, Huainan, P. R. China.,Wuhan Zhongke Optics Valley Green Biotechnology Co. Ltd., Wuhan, China
| | - Zhongkui Li
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, P. R. China.,Science Island Branch of Graduate School , University of Science & Technology of China, Hefei, P. R. China
| | - Lixia Yuan
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, P. R. China
| | - Yu Wang
- Wuhan Zhongke Optics Valley Green Biotechnology Co. Ltd., Wuhan, China
| | - Xiangsong Chen
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, P. R. China.,Huainan New Energy Research Center, Institute of Plasma Physics, Chinese Academy of Sciences, Huainan, P. R. China
| | - Jianming Yao
- Institute of Plasma Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, P. R. China.,Science Island Branch of Graduate School , University of Science & Technology of China, Hefei, P. R. China
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6
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Shimada T, Yokoyama Y, Anzai T, Yamamoto K, Ishihama A. Regulatory Role of PlaR (YiaJ) for Plant Utilization in Escherichia coli K-12. Sci Rep 2019; 9:20415. [PMID: 31892694 PMCID: PMC6958661 DOI: 10.1038/s41598-019-56886-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022] Open
Abstract
Outside a warm-blooded animal host, the enterobacterium Escherichia coli K-12 is also able to grow and survive in stressful nature. The major organic substance in nature is plant, but the genetic system of E. coli how to utilize plant-derived materials as nutrients is poorly understood. Here we describe the set of regulatory targets for uncharacterized IclR-family transcription factor YiaJ on the E. coli genome, using gSELEX screening system. Among a total of 18 high-affinity binding targets of YiaJ, the major regulatory target was identified to be the yiaLMNOPQRS operon for utilization of ascorbate from fruits and galacturonate from plant pectin. The targets of YiaJ also include the genes involved in the utilization for other plant-derived materials as nutrients such as fructose, sorbitol, glycerol and fructoselysine. Detailed in vitro and in vivo analyses suggest that L-ascorbate and α-D-galacturonate are the effector ligands for regulation of YiaJ function. These findings altogether indicate that YiaJ plays a major regulatory role in expression of a set of the genes for the utilization of plant-derived materials as nutrients for survival. PlaR was also suggested to play protecting roles of E. coli under stressful environments in nature, including the formation of biofilm. We then propose renaming YiaJ to PlaR (regulator of plant utilization). The natural hosts of enterobacterium Escherichia coli are warm-blooded animals, but even outside hosts, E. coli can survive even under stressful environments. On earth, the most common organic materials to be used as nutrients by E. coli are plant-derived components, but up to the present time, the genetic system of E. coli for plant utilization is poorly understand. In the course of gSELEX screening of the regulatory targets for hitherto uncharacterized TFs, we identified in this study the involvement of the IclR-family YiaJ in the regulation of about 20 genes or operons, of which the majority are related to the catabolism of plant-derived materials such as ascorbate, galacturonate, sorbitol, fructose and fructoselysine. Therefore, we propose to rename YiaJ to PlaR (regulator of plant utilization).
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Affiliation(s)
- Tomohiro Shimada
- Meiji University, School of Agriculture, Kawasaki, Kanagawa, 214-8571, Japan. .,Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-0003, Japan.
| | - Yui Yokoyama
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Takumi Anzai
- Meiji University, School of Agriculture, Kawasaki, Kanagawa, 214-8571, Japan
| | - Kaneyoshi Yamamoto
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Akira Ishihama
- Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-0003, Japan. .,Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan.
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7
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Xu YF, Lu W, Chen JC, Johnson SA, Gibney PA, Thomas DG, Brown G, May AL, Campagna SR, Yakunin AF, Botstein D, Rabinowitz JD. Discovery and Functional Characterization of a Yeast Sugar Alcohol Phosphatase. ACS Chem Biol 2018; 13:3011-3020. [PMID: 30240188 DOI: 10.1021/acschembio.8b00804] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Sugar alcohols (polyols) exist widely in nature. While some specific sugar alcohol phosphatases are known, there is no known phosphatase for some important sugar alcohols (e.g., sorbitol-6-phosphate). Using liquid chromatography-mass spectrometry-based metabolomics, we screened yeast strains with putative phosphatases of unknown function deleted. We show that the yeast gene YNL010W, which has close homologues in all fungi species and some plants, encodes a sugar alcohol phosphatase. We term this enzyme, which hydrolyzes sorbitol-6-phosphate, ribitol-5-phosphate, and (d)-glycerol-3-phosphate, polyol phosphatase 1 or PYP1. Polyol phosphates are structural analogs of the enediol intermediate of phosphoglucose isomerase (Pgi). We find that sorbitol-6-phosphate and ribitol-5-phosphate inhibit Pgi and that Pyp1 activity is important for yeast to maintain Pgi activity in the presence of environmental sugar alcohols. Pyp1 expression is strongly positively correlated with yeast growth rate, presumably because faster growth requires greater glycolytic and accordingly Pgi flux. Thus, yeast express the previously uncharacterized enzyme Pyp1 to prevent inhibition of glycolysis by sugar alcohol phosphates. Pyp1 may be useful for engineering sugar alcohol production.
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Affiliation(s)
- Yi-Fan Xu
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Wenyun Lu
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
| | - Jonathan C. Chen
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Sarah A. Johnson
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Patrick A. Gibney
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
| | - David G. Thomas
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
| | - Greg Brown
- Department of Chemical Engineering and Applied Chemistry, Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Amanda L. May
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Shawn R. Campagna
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Alexander F. Yakunin
- Department of Chemical Engineering and Applied Chemistry, Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - David Botstein
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Joshua D. Rabinowitz
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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8
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Salomone-Stagni M, Bartho JD, Kalita E, Rejzek M, Field RA, Bellini D, Walsh MA, Benini S. Structural and functional analysis of Erwinia amylovora SrlD. The first crystal structure of a sorbitol-6-phosphate 2-dehydrogenase. J Struct Biol 2018; 203:109-119. [PMID: 29605571 DOI: 10.1016/j.jsb.2018.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 10/17/2022]
Abstract
Sorbitol-6-phosphate 2-dehydrogenases (S6PDH) catalyze the interconversion of d-sorbitol 6-phosphate to d-fructose 6-phosphate. In the plant pathogen Erwinia amylovora the S6PDH SrlD is used by the bacterium to utilize sorbitol, which is used for carbohydrate transport in the host plants belonging to the Amygdaloideae subfamily (e.g., apple, pear, and quince). We have determined the crystal structure of S6PDH SrlD at 1.84 Å resolution, which is the first structure of an EC 1.1.1.140 enzyme. Kinetic data show that SrlD is much faster at oxidizing d-sorbitol 6-phosphate than in reducing d-fructose 6-phosphate, however, equilibrium analysis revealed that only part of the d-sorbitol 6-phosphate present in the in vitro environment is converted into d-fructose 6-phosphate. The comparison of the structures of SrlD and Rhodobacter sphaeroides sorbitol dehydrogenase showed that the tetrameric quaternary structure, the catalytic residues and a conserved aspartate residue that confers specificity for NAD+ over NADP+ are preserved. Analysis of the SrlD cofactor and substrate binding sites identified residues important for the formation of the complex with cofactor and substrate and in particular the role of Lys42 in selectivity towards the phospho-substrate. The comparison of SrlD backbone with the backbone of 302 short-chain dehydrogenases/reductases showed the conservation of the protein core and identified the variable parts. The SrlD sequence was compared with 500 S6PDH sequences selected by homology revealing that the C-terminal part is more conserved than the N-terminal, the consensus of the catalytic tetrad (Y[SN]AGXA) and a not previously described consensus for the NAD(H) binding.
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Affiliation(s)
- Marco Salomone-Stagni
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy
| | - Joseph D Bartho
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy; Gene Center of the LMU Department of Biochemistry, Feodor-Lynen Strasse 25, D-81377 Munich, Germany
| | - Eeshan Kalita
- Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur, Assam 784028, India
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Dom Bellini
- School of Life Science, Gibbet Hill, Warwick University, Coventry CV4 7AL, UK; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK; Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0FA, UK
| | - Martin A Walsh
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK; Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0FA, UK
| | - Stefano Benini
- Bioorganic Chemistry and Bio-Crystallography Laboratory (B(2)Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
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9
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Abstract
Pyruvate and acetyl-CoA form the backbone of central metabolism. The nonoxidative cleavage of pyruvate to acetyl-CoA and formate by the glycyl radical enzyme pyruvate formate lyase is one of the signature reactions of mixed-acid fermentation in enterobacteria. Under these conditions, formic acid accounts for up to one-third of the carbon derived from glucose. The further metabolism of acetyl-CoA to acetate via acetyl-phosphate catalyzed by phosphotransacetylase and acetate kinase is an exemplar of substrate-level phosphorylation. Acetyl-CoA can also be used as an acceptor of the reducing equivalents generated during glycolysis, whereby ethanol is formed by the polymeric acetaldehyde/alcohol dehydrogenase (AdhE) enzyme. The metabolism of acetyl-CoA via either the acetate or the ethanol branches is governed by the cellular demand for ATP and the necessity to reoxidize NADH. Consequently, in the absence of an electron acceptor mutants lacking either branch of acetyl-CoA metabolism fail to cleave pyruvate, despite the presence of PFL, and instead reduce it to D-lactate by the D-lactate dehydrogenase. The conversion of PFL to the active, radical-bearing species is controlled by a radical-SAM enzyme, PFL-activase. All of these reactions are regulated in response to the prevalent cellular NADH:NAD+ ratio. In contrast to Escherichia coli and Salmonella species, some genera of enterobacteria, e.g., Klebsiella and Enterobacter, produce the more neutral product 2,3-butanediol and considerable amounts of CO2 as fermentation products. In these bacteria, two molecules of pyruvate are converted to α-acetolactate (AL) by α-acetolactate synthase (ALS). AL is then decarboxylated and subsequently reduced to the product 2,3-butandiol.
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10
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Islam MA, Tchigvintsev A, Yim V, Savchenko A, Yakunin AF, Mahadevan R, Edwards EA. Experimental validation of in silico model-predicted isocitrate dehydrogenase and phosphomannose isomerase from Dehalococcoides mccartyi. Microb Biotechnol 2015; 9:47-60. [PMID: 26374290 PMCID: PMC4720418 DOI: 10.1111/1751-7915.12315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 07/12/2015] [Accepted: 08/07/2015] [Indexed: 11/28/2022] Open
Abstract
Gene sequences annotated as proteins of unknown or non‐specific function and hypothetical proteins account for a large fraction of most genomes. In the strictly anaerobic and organohalide respiring Dehalococcoides mccartyi, this lack of annotation plagues almost half the genome. Using a combination of bioinformatics analyses and genome‐wide metabolic modelling, new or more specific annotations were proposed for about 80 of these poorly annotated genes in previous investigations of D. mccartyi metabolism. Herein, we report the experimental validation of the proposed reannotations for two such genes (KB1_0495 and KB1_0553) from D. mccartyi strains in the KB‐1 community. KB1_0495 or DmIDH was originally annotated as an NAD+‐dependent isocitrate dehydrogenase, but biochemical assays revealed its activity primarily with NADP+ as a cofactor. KB1_0553, also denoted as DmPMI, was originally annotated as a hypothetical protein/sugar isomerase domain protein. We previously proposed that it was a bifunctional phosphoglucose isomerase/phosphomannose isomerase, but only phosphomannose isomerase activity was identified and confirmed experimentally. Further bioinformatics analyses of these two protein sequences suggest their affiliation to potentially novel enzyme families within their respective larger enzyme super families.
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Affiliation(s)
- M Ahsanul Islam
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
| | - Anatoli Tchigvintsev
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
| | - Veronica Yim
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, M5S 3E5, Canada
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Bonin P, Groisillier A, Raimbault A, Guibert A, Boyen C, Tonon T. Molecular and biochemical characterization of mannitol-1-phosphate dehydrogenase from the model brown alga Ectocarpus sp. PHYTOCHEMISTRY 2015; 117:509-520. [PMID: 26232554 DOI: 10.1016/j.phytochem.2015.07.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/16/2015] [Accepted: 07/20/2015] [Indexed: 06/04/2023]
Abstract
The sugar alcohol mannitol is important in the food, pharmaceutical, medical and chemical industries. It is one of the most commonly occurring polyols in nature, with the exception of Archaea and animals. It has a range of physiological roles, including as carbon storage, compatible solute, and osmolyte. Mannitol is present in large amounts in brown algae, where its synthesis involved two steps: a mannitol-1-phosphate dehydrogenase (M1PDH) catalyzes a reversible reaction between fructose-6-phosphate (F6P) and mannitol-1-phosphate (M1P) (EC 1.1.1.17), and a mannitol-1-phosphatase hydrolyzes M1P to mannitol (EC 3.1.3.22). Analysis of the model brown alga Ectocarpus sp. genome provided three candidate genes for M1PDH activities. We report here the sequence analysis of Ectocarpus M1PDHs (EsM1PDHs), and the biochemical characterization of the recombinant catalytic domain of EsM1PDH1 (EsM1PDH1cat). Ectocarpus M1PDHs are representatives of a new type of modular M1PDHs among the polyol-specific long-chain dehydrogenases/reductases (PSLDRs). The N-terminal domain of EsM1PDH1 was not necessary for enzymatic activity. Determination of kinetic parameters indicated that EsM1PDH1cat displayed higher catalytic efficiency for F6P reduction compared to M1P oxidation. Both activities were influenced by NaCl concentration and inhibited by the thioreactive compound pHMB. These observations were completed by measurement of endogenous M1PDH activity and of EsM1PDH gene expression during one diurnal cycle. No significant changes in enzyme activity were monitored between day and night, although transcription of two out of three genes was altered, suggesting different levels of regulation for this key metabolic pathway in brown algal physiology.
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Affiliation(s)
- Patricia Bonin
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Agnès Groisillier
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Alice Raimbault
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Anaïs Guibert
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Catherine Boyen
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
| | - Thierry Tonon
- Sorbonne Université, UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France.
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The mannitol utilization system of the marine bacterium Zobellia galactanivorans. Appl Environ Microbiol 2014; 81:1799-812. [PMID: 25548051 DOI: 10.1128/aem.02808-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mannitol is a polyol that occurs in a wide range of living organisms, where it fulfills different physiological roles. In particular, mannitol can account for as much as 20 to 30% of the dry weight of brown algae and is likely to be an important source of carbon for marine heterotrophic bacteria. Zobellia galactanivorans (Flavobacteriia) is a model for the study of pathways involved in the degradation of seaweed carbohydrates. Annotation of its genome revealed the presence of genes potentially involved in mannitol catabolism, and we describe here the biochemical characterization of a recombinant mannitol-2-dehydrogenase (M2DH) and a fructokinase (FK). Among the observations, the M2DH of Z. galactanivorans was active as a monomer, did not require metal ions for catalysis, and featured a narrow substrate specificity. The FK characterized was active on fructose and mannose in the presence of a monocation, preferentially K(+). Furthermore, the genes coding for these two proteins were adjacent in the genome and were located directly downstream of three loci likely to encode an ATP binding cassette (ABC) transporter complex, suggesting organization into an operon. Gene expression analysis supported this hypothesis and showed the induction of these five genes after culture of Z. galactanivorans in the presence of mannitol as the sole source of carbon. This operon for mannitol catabolism was identified in only 6 genomes of Flavobacteriaceae among the 76 publicly available at the time of the analysis. It is not conserved in all Bacteroidetes; some species contain a predicted mannitol permease instead of a putative ABC transporter complex upstream of M2DH and FK ortholog genes.
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Hobbs ME, Vetting M, Williams HJ, Narindoshvili T, Kebodeaux DM, Hillerich B, Seidel RD, Almo SC, Raushel FM. Discovery of an L-fucono-1,5-lactonase from cog3618 of the amidohydrolase superfamily. Biochemistry 2012; 52:239-53. [PMID: 23214453 DOI: 10.1021/bi3015554] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A member of the amidohydrolase superfamily, BmulJ_04915 from Burkholderia multivorans, of unknown function was determined to hydrolyze a series of sugar lactones: L-fucono-1,4-lactone, D-arabino-1,4-lactone, L-xylono-1,4-lactone, D-lyxono-1,4-lactone, and L-galactono-1,4-lactone. The highest activity was shown for L-fucono-1,4-lactone with a k(cat) value of 140 s(-1) and a k(cat)/K(m) value of 1.0 × 10(5) M(-1) s(-1) at pH 8.3. The enzymatic product of an adjacent L-fucose dehydrogenase, BmulJ_04919, was shown to be L-fucono-1,5-lactone via nuclear magnetic resonance spectroscopy. L-Fucono-1,5-lactone is unstable and rapidly converts nonenzymatically to L-fucono-1,4-lactone. Because of the chemical instability of L-fucono-1,5-lactone, 4-deoxy-L-fucono-1,5-lactone was enzymatically synthesized from 4-deoxy-L-fucose using L-fucose dehydrogenase. BmulJ_04915 hydrolyzed 4-deoxy-L-fucono-1,5-lactone with a k(cat) value of 990 s(-1) and a k(cat)/K(m) value of 8.0 × 10(6) M(-1) s(-1) at pH 7.1. The protein does not require divalent cations in the active site for catalytic activity. BmulJ_04915 is the second enzyme from cog3618 of the amidohydrolase superfamily that does not require a divalent metal for catalytic activity. BmulJ_04915 is the first enzyme that has been shown to catalyze the hydrolysis of either L-fucono-1,4-lactone or L-fucono-1,5-lactone. The structures of the fuconolactonase and the fucose dehydrogenase were determined by X-ray diffraction methods.
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Affiliation(s)
- Merlin Eric Hobbs
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
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Expression profile of miRNAs in Populus cathayana L. and Salix matsudana Koidz under salt stress. Mol Biol Rep 2012; 39:8645-54. [PMID: 22718503 DOI: 10.1007/s11033-012-1719-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 06/06/2012] [Indexed: 01/01/2023]
Abstract
Soil salinization can lead to environmental and ecological problems worldwide. Abiotic stressors, including salinity, are suspected to regulate microRNA (miRNA) expression. Plants exposed to such abiotic stressors express specific miRNAs, which are genes encoding small non-coding RNAs of 20-24 nucleotides. miRNAs are known to exist widely in plant genomes, and are endogenous. A previous study used miRNA microarray technology and poly(A) polymerase-mediated qRT-PCR technology to analyze the expression profile of miRNAs in two types of plants, Populus cathayana L. (salt-sensitive plants) and Salix matsudana Koidz (highly salinity-tolerant plants), both belonging to the Salicaceae family. miRNA microarray hybridization revealed changes in expression of 161 miRNAs P. cathayana and 32 miRNAs in S. matsudana under salt stress. Differences in expression indicate that the same miRNA has different expression patterns in salt-sensitive plants and salt-tolerant plants under salt stress. These indicate that changes in expression of miRNAs might function as a response to varying salt concentrations. To examine this, we used qRT-PCR to select five miRNA family target genes involved in plant responses to salt stress. Upon saline treatment, the expressions of both ptc-miR474c and ptc-miR398b in P. cathayana were down-regulated, but were up-regulated in S. matsudana. Expression of the miR396 family in both types of plants was suppressed. Furthermore, we have analyzed the different expression patterns between P. cathayana and S. matsudana. Findings of this study can be utilized in future investigations of post-transcriptional gene regulation in P. cathayana and S. matsudana under saline stress.
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Jain VK, Divol B, Prior BA, Bauer FF. Effect of alternative NAD+-regenerating pathways on the formation of primary and secondary aroma compounds in a Saccharomyces cerevisiae glycerol-defective mutant. Appl Microbiol Biotechnol 2011; 93:131-41. [PMID: 21720823 DOI: 10.1007/s00253-011-3431-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 05/26/2011] [Accepted: 05/29/2011] [Indexed: 12/01/2022]
Abstract
Saccharomyces cerevisiae maintains a redox balance under fermentative growth conditions by re-oxidizing NADH formed during glycolysis through ethanol formation. Excess NADH stimulates the synthesis of mainly glycerol, but also of other compounds. Here, we investigated the production of primary and secondary metabolites in S. cerevisiae strains where the glycerol production pathway was inactivated through deletion of the two glycerol-3-phosphate dehydrogenases genes (GPD1/GPD2) and replaced with alternative NAD(+)-generating pathways. While these modifications decreased fermentative ability compared to the wild-type strain, all improved growth and/or fermentative ability of the gpd1Δgpd2Δ strain in self-generated anaerobic high sugar medium. The partial NAD(+) regeneration ability of the mutants resulted in significant amounts of alternative products, but at lower yields than glycerol. Compared to the wild-type strain, pyruvate production increased in most genetically manipulated strains, whereas acetate and succinate production decreased in all strains. Malate production was similar in all strains. Isobutanol production increased substantially in all genetically manipulated strains compared to the wild-type strain, whereas only mutant strains expressing the sorbitol producing SOR1 and srlD genes showed increases in isoamyl alcohol and 2-phenyl alcohol. A marked reduction in ethyl acetate concentration was observed in the genetically manipulated strains, while isobutyric acid increased. The synthesis of some primary and secondary metabolites appears more readily influenced by the NAD(+)/NADH availability. The data provide an initial assessment of the impact of redox balance on the production of primary and secondary metabolites which play an essential role in the flavour and aroma character of beverages.
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Affiliation(s)
- Vishist K Jain
- Institute for Wine Biotechnology, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, South Africa
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16
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Characterization of the mannitol catabolic operon of Corynebacterium glutamicum. Appl Microbiol Biotechnol 2011; 91:1375-87. [DOI: 10.1007/s00253-011-3352-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/20/2011] [Accepted: 04/20/2011] [Indexed: 10/18/2022]
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17
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Elimination of glycerol and replacement with alternative products in ethanol fermentation by Saccharomyces cerevisiae. J Ind Microbiol Biotechnol 2010; 38:1427-35. [PMID: 21188613 DOI: 10.1007/s10295-010-0928-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 12/06/2010] [Indexed: 10/18/2022]
Abstract
Glycerol is a major by-product of ethanol fermentation by Saccharomyces cerevisiae and typically 2-3% of the sugar fermented is converted to glycerol. Replacing the NAD(+)-regenerating glycerol pathway in S. cerevisiae with alternative NADH reoxidation pathways may be useful to produce metabolites of biotechnological relevance. Under fermentative conditions yeast reoxidizes excess NADH through glycerol production which involves NADH-dependent glycerol-3-phosphate dehydrogenases (Gpd1p and Gpd2p). Deletion of these two genes limits fermentative activity under anaerobic conditions due to accumulation of NADH. We investigated the possibility of converting this excess NADH to NAD(+) by transforming a double mutant (gpd1∆gpd2∆) with alternative oxidoreductase genes that might restore the redox balance and produce either sorbitol or propane-1,2-diol. All of the modifications improved fermentative ability and/or growth of the double mutant strain in a self-generated anaerobic high sugar medium. However, these strain properties were not restored to the level of the parental wild-type strain. The results indicate an apparent partial NAD(+) regeneration ability and formation of significant amounts of the commodity chemicals like sorbitol or propane-1,2-diol. The ethanol yields were maintained between 46 and 48% of the sugar mixture. Other factors apart from the maintenance of the redox balance appeared to influence the growth and production of the alternative products by the genetically manipulated strains.
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18
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Roux C, Salmon L, Verchère-Béaur C. Preliminary studies on the inhibition of D-sorbitol-6-phosphate 2–dehydrogenase fromEscherichia coliwith substrate analogues. J Enzyme Inhib Med Chem 2008; 21:187-92. [PMID: 16791965 DOI: 10.1080/14756360500535260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
D-Sorbitol-6-phosphate 2-dehydrogenase catalyzes the NADH-dependent conversion of D-fructose 6-phosphate to D-sorbitol 6-phosphate and improved production and purification of the enzyme from Escherichia coli is reported. Preliminary inhibition studies of the enzyme revealed 5-phospho-D-arabinonohydroxamic acid and 5-phospho-D-arabinonate as new substrate analogue inhibitors of the F6P catalyzed reduction with IC50 values of (40 +/- 1) microM and (48 +/- 3) microM and corresponding Km/IC50 ratio values of 14 and 12, respectively. Furthermore, we report here the phosphomannose isomerase substrate D-mannose 6-phosphate as the best inhibitor of E. coli D-sorbitol-6-phosphate 2-dehydrogenase yet reported with an IC50 = 7.5 +/- 0.4 microM and corresponding Km/IC50 ratio = about 76.
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Affiliation(s)
- Céline Roux
- Laboratoire de Chimie Bioorganique et Bioinorganique, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8124, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Bâtiment 420, Université Paris-Sud XI, 91405 Orsay Cedex, France
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19
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Canelas AB, van Gulik WM, Heijnen JJ. Determination of the cytosolic free NAD/NADH ratio in Saccharomyces cerevisiae under steady-state and highly dynamic conditions. Biotechnol Bioeng 2008; 100:734-43. [PMID: 18383140 DOI: 10.1002/bit.21813] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The coenzyme NAD plays a major role in metabolism as a key redox carrier and signaling molecule but current measurement techniques cannot distinguish between different compartment pools, between free and protein-bound forms and/or between NAD(H) and NADP(H). Local free NAD/NADH ratios can be determined from product/substrate ratios of suitable near-equilibrium redox reactions but the application of this principle is often precluded by uncertainties regarding enzyme activity, localization and coenzyme specificity of dehydrogenases. In Saccharomyces cerevisiae, we circumvented these issues by expressing a bacterial mannitol-1-phosphate 5-dehydrogenase and determining the cytosolic free NAD/NADH ratio from the measured [fructose-6-phosphate]/[mannitol-1-phosphate] ratio. Under aerobic glucose-limited conditions we estimated a cytosolic free NAD/NADH ratio between 101(+/-14) and 320(+/-45), assuming the cytosolic pH is between 7.0 and 6.5, respectively. These values are more than 10-fold higher than the measured whole-cell total NAD/NADH ratio of 7.5(+/-2.5). Using a thermodynamic analysis of central glycolysis we demonstrate that the former are thermodynamically feasible, while the latter is not. Furthermore, we applied this novel system to study the short-term metabolic responses to perturbations. We found that the cytosolic free NAD-NADH couple became more reduced rapidly (timescale of seconds) upon a pulse of glucose (electron-donor) and that this could be reversed by the addition of acetaldehyde (electron-acceptor). In addition, these dynamics occurred without significant changes in whole-cell total NAD and NADH. This approach provides a new experimental tool for quantitative physiology and opens new possibilities in the study of energy and redox metabolism in S. cerevisiae. The same strategy should also be applicable to other microorganisms.
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Affiliation(s)
- André B Canelas
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628BC Delft, The Netherlands
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Characterization of recombinant Aspergillus fumigatus mannitol-1-phosphate 5-dehydrogenase and its application for the stereoselective synthesis of protio and deuterio forms of D-mannitol 1-phosphate. Carbohydr Res 2008; 343:1414-23. [PMID: 18452897 DOI: 10.1016/j.carres.2008.04.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 04/02/2008] [Accepted: 04/04/2008] [Indexed: 11/22/2022]
Abstract
A putative long-chain mannitol-1-phosphate 5-dehydrogenase from Aspergillus fumigatus (AfM1PDH) was overexpressed in Escherichia coli to a level of about 50% of total intracellular protein. The purified recombinant protein was a approximately 40-kDa monomer in solution and displayed the predicted enzymatic function, catalyzing NAD(H)-dependent interconversion of d-mannitol 1-phosphate and d-fructose 6-phosphate with a specific reductase activity of 170 U/mg at pH 7.1 and 25 degrees C. NADP(H) showed a marginal activity. Hydrogen transfer from formate to d-fructose 6-phosphate, mediated by NAD(H) and catalyzed by a coupled enzyme system of purified Candida boidinii formate dehydrogenase and AfM1PDH, was used for the preparative synthesis of d-mannitol 1-phosphate or, by applying an analogous procedure using deuterio formate, the 5-[2H] derivative thereof. Following the precipitation of d-mannitol 1-phosphate as barium salt, pure product (>95% by HPLC and NMR) was obtained in isolated yields of about 90%, based on 200 mM of d-fructose 6-phosphate employed in the reaction. In situ proton NMR studies of enzymatic oxidation of d-5-[2H]-mannitol 1-phosphate demonstrated that AfM1PDH was stereospecific for transferring the deuterium to NAD+, producing (4S)-[2H]-NADH. Comparison of maximum initial rates for NAD+-dependent oxidation of protio and deuterio forms of D-mannitol 1-phosphate at pH 7.1 and 25 degrees C revealed a primary kinetic isotope effect of 2.9+/-0.2, suggesting that the hydride transfer was strongly rate-determining for the overall enzymatic reaction under these conditions.
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Jeffery J, Jörnvall H. Sorbitol dehydrogenase. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 61:47-106. [PMID: 3281420 DOI: 10.1002/9780470123072.ch2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- J Jeffery
- Department of Biochemistry, University of Aberdeen, Scotland, UK
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22
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Meredith TC, Woodard RW. Identification of GutQ from Escherichia coli as a D-arabinose 5-phosphate isomerase. J Bacteriol 2005; 187:6936-42. [PMID: 16199563 PMCID: PMC1251629 DOI: 10.1128/jb.187.20.6936-6942.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The glucitol operon (gutAEBDMRQ) of Escherichia coli encodes a phosphoenolpyruvate:sugar phosphotransferase system that metabolizes the hexitol D-glucitol (sorbitol). The functions for all but the last gene, gutQ, have been previously assigned. The high sequence similarity between GutQ and KdsD, a D-arabinose 5-phosphate isomerase (API) from the 3-deoxy-D-manno-octulosonate (KDO)-lipopolysaccharide (LPS) biosynthetic pathway, suggested a putative activity, but its role within the context of the gut operon remained unclear. Accordingly, the enzyme was cloned, overexpressed, and characterized. Recombinant GutQ was shown to indeed be a second copy of API from the E. coli K-12 genome with biochemical properties similar to those of KdsD, catalyzing the reversible aldol-ketol isomerization between D-ribulose 5-phosphate (Ru5P) and D-arabinose 5-phosphate (A5P). Genomic disruptions of each API gene were constructed in E. coli K-12. TCM11[(deltakdsD)] was capable of sustaining essential LPS synthesis at wild-type levels, indicating that GutQ functions as an API inside the cell. The gut operon remained inducible in TCM7[(deltagutQ)], suggesting that GutQ is not directly involved in d-glucitol catabolism. The conditional mutant TCM15[(deltagutQdeltakdsD)] was dependent on exogenous A5P both for LPS synthesis/growth and for upregulation of the gut operon. The phenotype was suppressed by complementation in trans with a plasmid encoding a functional copy of GutQ or by increasing the amount of A5P in the medium. As there is no obvious obligatory role for GutQ in the metabolism of d-glucitol and there is no readily apparent link between D-glucitol metabolism and LPS biosynthesis, it is suggested that A5P is not only a building block for KDO biosynthesis but also may be a regulatory molecule involved in expression of the gut operon.
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Affiliation(s)
- Timothy C Meredith
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor 48109-1065, USA
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23
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Abstract
Escherichia coli and Salmonella enterica serovar Typhimurium exhibit a remarkable versatility in the usage of different sugars as the sole source of carbon and energy, reflecting their ability to make use of the digested meals of mammalia and of the ample offerings in the wild. Degradation of sugars starts with their energy-dependent uptake through the cytoplasmic membrane and is carried on further by specific enzymes in the cytoplasm, destined finally for degradation in central metabolic pathways. As variant as the different sugars are, the biochemical strategies to act on them are few. They include phosphorylation, keto-enol isomerization, oxido/reductions, and aldol cleavage. The catabolic repertoire for using carbohydrate sources is largely the same in E. coli and in serovar Typhimurium. Nonetheless, significant differences are found, even among the strains and substrains of each species. We have grouped the sugars to be discussed according to their first step in metabolism, which is their active transport, and follow their path to glycolysis, catalyzed by the sugar-specific enzymes. We will first discuss the phosphotransferase system (PTS) sugars, then the sugars transported by ATP-binding cassette (ABC) transporters, followed by those that are taken up via proton motive force (PMF)-dependent transporters. We have focused on the catabolism and pathway regulation of hexose and pentose monosaccharides as well as the corresponding sugar alcohols but have also included disaccharides and simple glycosides while excluding polysaccharide catabolism, except for maltodextrins.
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Affiliation(s)
- Christoph Mayer
- Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany
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Iwamoto K, Shiraiwa Y. Salt-regulated mannitol metabolism in algae. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2005; 7:407-15. [PMID: 16088352 DOI: 10.1007/s10126-005-0029-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2005] [Accepted: 04/28/2005] [Indexed: 05/03/2023]
Abstract
Mannitol, one of the most widely occurring sugar alcohol compounds, is found in bacteria, fungi, algae, and plants. In these organisms the compound acts as a compatible solute and has multiple functions, including osmoregulation, storage, and regeneration of reducing power, and scavenging of active oxygen species. Because of the diverse functions of mannitol, introducing the ability to accumulate it has been a hallmark of attempts to generate highly salt-tolerant transgenic plants. However, transgenic plants have not yet improved significantly in their salt tolerance. Recently, we purified and characterized 2 enzymes that biosynthesize mannitol, mannitol-1-phosphate dehydrogenase (M1PDH) and mannitol-1-phosphate-specific phosphatase, from the marine red alga Caloglossa continua, which grows in estuarine areas where tide levels fluctuate frequently. The activation of Caloglossa M1PDH is unique in that it is regulated by salt concentration at enzyme level. In this review we focus on the metabolism of mannitol, mainly in marine photosynthetic organisms, and suggest how this might be applied to producing salt-tolerant transgenic plants.
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Affiliation(s)
- Koji Iwamoto
- Functional Biosciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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Iwamoto K, Kawanobe H, Ikawa T, Shiraiwa Y. Characterization of salt-regulated mannitol-1-phosphate dehydrogenase in the red alga Caloglossa continua. PLANT PHYSIOLOGY 2003; 133:893-900. [PMID: 12972650 PMCID: PMC219062 DOI: 10.1104/pp.103.026906] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2003] [Revised: 06/11/2003] [Accepted: 07/05/2003] [Indexed: 05/19/2023]
Abstract
Mannitol-1-phosphate (M1P) dehydrogenase (M1PDH; EC 1.1.1.17), an enzyme catalyzing the reduction of Fru-6-phosphate (F6P) to M1P in algal mannitol biosynthesis, was purified to homogeneity from a cell homogenate of the eulittoral red alga Caloglossa continua (Okamura) King et Puttock. The enzyme was a monomer with an apparent molecular mass of 53 kD, as determined by gel filtration and SDS-PAGE, and exhibited an pI of approximately 5.5. The substrate specificity was very high toward F6P and M1P for respective reductive and oxidative reactions. The enzyme was found to be a sulfhydryl-type, because its activity was inhibited by N-ethylmaleimide and p-hydroxymercuribenzoate, and the inhibition by p-hydroxymercuribenzoate was rescued by 2-mercaptoethanol. Some unknown factors in the extract may also have inhibited the activity, because the total activity was greatly increased through the purification procedure. The optimum pH for F6P reduction was changed from 6.0 or lower to 7.2 by the addition of 200 mm NaCl. The reduction of F6P showed strong substrate inhibition above 0.5 mm. However, Km(F6P) of M1PDH was increased eight times by the addition of 200 mm NaCl, whereas Vmax was in a similar range with the avoidance of substrate inhibition by F6P. These results indicate that the enzyme was finely and directly regulated by the salt concentration without the requirement for gene expression. M1PDH can therefore be a key enzyme for regulating mannitol biosynthesis when the alga is stressed by a salinity change.
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Affiliation(s)
- Koji Iwamoto
- Institute of Biological Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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26
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Povelainen M, Eneyskaya EV, Kulminskaya AA, Ivanen DR, Kalkkinen N, Neustroev KN, Miasnikov AN. Biochemical and genetic characterization of a novel enzyme of pentitol metabolism: D-arabitol-phosphate dehydrogenase. Biochem J 2003; 371:191-7. [PMID: 12467497 PMCID: PMC1223252 DOI: 10.1042/bj20021096] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2002] [Revised: 11/20/2002] [Accepted: 12/06/2002] [Indexed: 11/17/2022]
Abstract
An enzyme with a specificity that has not been described previously, D-arabitol-phosphate dehydrogenase (APDH), has been purified from cell lysate of Enterococcus avium. SDS/PAGE indicated that the enzyme had a molecular mass of 41+/-2 kDa, whereas a molecular mass of 160+/-5 kDa was observed under non-denaturing conditions, implying that the APDH may exist as a tetramer with identical subunits. Purified APDH was found to have a narrow substrate specificity, converting only D-arabitol 1-phosphate and D-arabitol 5-phosphate into xylulose 5-phosphate and ribulose 5-phosphate, respectively, in the oxidative reaction. Both NAD(+) and NADP(+) were accepted as cofactors. Based on the partial protein sequences, the APDH gene was cloned. Homology comparisons place APDH within the medium-range dehydrogenase family. Unlike most members of this family, APDH requires Mn(2+) but no Zn(2+) for enzymic activity. The DNA sequence surrounding the gene suggests that it belongs to an operon that also contains several components of phosphotransferase system. Both biochemical evidence and protein sequence homology comparisons indicate that similar enzymes are widespread among the Gram-positive bacteria. Their apparent biological role is to participate in arabitol catabolism via the 'arabitol phosphate route', similar to the ribitol and xylitol catabolic routes described previously.
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Affiliation(s)
- Mira Povelainen
- Danisco Cultor Innovation, Sokeritehtaantie 20, Kantvik 02460, Finland
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27
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Costenoble R, Adler L, Niklasson C, Lidén G. Engineering of the metabolism of Saccharomyces cerevisiae for anaerobic production of mannitol. FEMS Yeast Res 2003; 3:17-25. [PMID: 12702242 DOI: 10.1111/j.1567-1364.2003.tb00134.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Under anaerobic conditions, Saccharomyces cerevisiae uses NADH-dependent glycerol-3-phosphate dehydrogenase (Gpd1p and Gpd2p) to re-oxidize excess NADH, yielding substantial amounts of glycerol. In a Deltagpd1 Deltagpd2 double-null mutant, the necessary NAD+ regeneration through glycerol production is no longer possible, and this mutant does not grow under anaerobic conditions. The excess NADH formed can potentially be used to drive other NADH-dependent reactions or pathways. To investigate this possibility, a double-null mutant was transformed with a heterologous gene (mtlD) from Escherichia coli, coding for NADH-dependent mannitol-1-phosphate dehydrogenase. Expression of this gene in S. cerevisiae should result in NADH oxidation by the NADH-requiring formation of mannitol-1-phosphate from fructose-6-phosphate. The strain was characterized using step-change experiments, in which, during the exponential growth phase, the inlet gas was changed from air to nitrogen. It was found that the mutant produced mannitol only under anaerobic conditions. However, anaerobic growth was not regained, which was probably due to the excessive accumulation of mannitol in the cells.
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Affiliation(s)
- Roeland Costenoble
- Chemical Reaction Engineering, Chalmers University of Technology, 41296, Göteborg, Sweden
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28
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Klimacek M, Kavanagh KL, Wilson DK, Nidetzky B. Pseudomonas fluorescens mannitol 2-dehydrogenase and the family of polyol-specific long-chain dehydrogenases/reductases: sequence-based classification and analysis of structure-function relationships. Chem Biol Interact 2003; 143-144:559-82. [PMID: 12604242 DOI: 10.1016/s0009-2797(02)00219-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Multiple sequence alignment and analysis of evolutionary relationships have been used to characterize a family of polyol-specific long-chain dehydrogenases/reductases (PSLDRs). At the present time, 66 known and putative NAD(P)H-dependent oxidoreductases of mainly prokaryotic origin and between 357 and 544 amino acids in length constitute this family. The family is shown to include D-mannitol 2-dehydrogenase, D-mannonate 5-oxidoreductase, D-altronate 5-oxidoreductase, D-arabinitol 4-dehydrogenase, and D-mannitol-1-phosphate 5-dehydrogenase which form individual sub-families (defined by internal sequence identity of >/=30%) having distant origin and divergent substrate specificity but clearly displaying entire-chain relationship. When all forms are aligned, only three residues, Gly-33, Asp-230, and Lys-295 (in the numbering of Pseudomonas fluorescens D-mannitol 2-dehydrogenase (PsM2DH)) are strictly conserved. By combining sequence alignment with the known structure of PsM2DH and results from site-directed mutagenesis, we have developed a structure/function analysis for the family. Gly-33 is in the N-terminal coenzyme-binding domain and part of a nucleotide fingerprint region for the family, and Asp-230 and Lys-295 are at an interdomain segment contributing to the active site in which the lysine likely functions as the catalytic general acid/base. PSLDRs do not require a metal cofactor for activity and are specific for transferring the 4-pro-S hydrogen from NAD(P)H. Comparisons reveal that the core part of the two-domain fold has been conserved throughout all family members, perhaps reflecting the recruitment of a stable oxidoreductase structure and extensive trimming thereof to acquire functional properties specific to each sub-family. They also identify interactions that define the chemical mechanism of oxidoreduction and likely contribute to substrate and co-substrate specificities and are thus relevant for protein engineering.
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Affiliation(s)
- Mario Klimacek
- Institute of Biotechnology, Graz University of Technology, Petersgasse 12/I, A-8010, Graz, Austria
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29
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Aboulwafa M, Saier MH. Dependency of sugar transport and phosphorylation by the phosphoenolpyruvate-dependent phosphotransferase system on membranous phosphatidyl glycerol in Escherichia coli: studies with a pgsA mutant lacking phosphatidyl glycerophosphate synthase. Res Microbiol 2002; 153:667-77. [PMID: 12558186 DOI: 10.1016/s0923-2508(02)01376-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
It has been reported that phosphatidyl glycerol (PG) is specifically required for the in vitro activities of the hexose-phosphorylating Enzymes II of the Escherichia coli phosphoenolpyruvate-dependent sugar transporting phosphotransferase system (PTS). We have examined this possibility by measuring the properties of a null pgsA mutant that lacks detectable PG. The mutant showed lower in vitro phosphorylation activities towards several sugars when both PEP-dependent and sugar-phosphate-dependent [14C]sugar phosphorylation reactions were measured. The order of dependency on PG for the different enzymes II was: IIMannose > IIGlucose > IIFructose > IIMannitol. Nonsedimentable (40000 rpm for 2 h) Enzymes II exhibited a greater dependency on PG than pelletable Enzymes II. Western blot analyses showed that the glucose Enzyme II is present in normal amounts. Transport and fermentation measurements revealed diminished activities for all Enzymes II. Thermal stability of all of these enzymes except the mannitol-specific Enzyme II was significantly decreased by the pgsA mutation, and sensitivity to detergent treatments was enhanced. Sugar transport proved to be the most sensitive indicator of proper Enzyme II-phospholipid association. Our results show that PG stimulates but is not required for Enzyme II function in E. coli.
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Affiliation(s)
- Mohammad Aboulwafa
- Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
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30
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Kavanagh KL, Klimacek M, Nidetzky B, Wilson DK. Crystal structure of Pseudomonas fluorescens mannitol 2-dehydrogenase binary and ternary complexes. Specificity and catalytic mechanism. J Biol Chem 2002; 277:43433-42. [PMID: 12196534 DOI: 10.1074/jbc.m206914200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Long-chain mannitol dehydrogenases are secondary alcohol dehydrogenases that are of wide interest because of their involvement in metabolism and potential applications in agriculture, medicine, and industry. They differ from other alcohol and polyol dehydrogenases because they do not contain a conserved tyrosine and are not dependent on Zn(2+) or other metal cofactors. The structures of the long-chain mannitol 2-dehydrogenase (54 kDa) from Pseudomonas fluorescens in a binary complex with NAD(+) and ternary complex with NAD(+) and d-mannitol have been determined to resolutions of 1.7 and 1.8 A and R-factors of 0.171 and 0.176, respectively. These results show an N-terminal domain that includes a typical Rossmann fold. The C-terminal domain is primarily alpha-helical and mediates mannitol binding. The electron lone pair of Lys-295 is steered by hydrogen-bonding interactions with the amide oxygen of Asn-300 and the main-chain carbonyl oxygen of Val-229 to act as the general base. Asn-191 and Asn-300 are involved in a web of hydrogen bonding, which precisely orients the mannitol O2 proton for abstraction. These residues also aid in stabilizing a negative charge in the intermediate state and in preventing the formation of nonproductive complexes with the substrate. The catalytic lysine may be returned to its unprotonated state using a rectifying proton tunnel driven by Glu-292 oscillating among different environments. Despite low sequence homology, the closest structural neighbors are glycerol-3-phosphate dehydrogenase, N-(1-d-carboxylethyl)-l-norvaline dehydrogenase, UDP-glucose dehydrogenase, and 6-phosphogluconate dehydrogenase, indicating a possible evolutionary relationship among these enzymes.
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Affiliation(s)
- Kathryn L Kavanagh
- Section of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
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31
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Otte S, Lengeler JW. The mtl genes and the mannitol-1-phosphate dehydrogenase from Klebsiella pneumoniae KAY2026. FEMS Microbiol Lett 2001; 194:221-7. [PMID: 11164312 DOI: 10.1111/j.1574-6968.2001.tb09473.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The mtl operon of Klebsiella pneumoniae KAY2026 (formerly Aerobacter aerogenes 1033-5P14) was shown to contain as the promoter-proximal gene mtlA, encoding a D-mannitol-specific enzyme II transporter (IICBA(Mtl)). This gene is followed by mtlD, coding for a mannitol-1-phosphate dehydrogenase (MtlD, 382 amino acid residues), and mtlR (MtlR, 195 amino acid residues) coding for a putative repressor, gene mtlR overlaps the termination codon of mtlD. The DNA and protein sequences are highly similar to the corresponding genes (81% identical bp) and proteins (79-85% identical amino acids) of Escherichia coli K-12. A truncated form of MtlD lacking the 162 C-terminal amino acid residues still shows 10% dehydrogenase activity which may explain the controversy in the literature concerning the properties of mannitol-phosphate and other medium-length dehydrogenases.
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Affiliation(s)
- S Otte
- Fachbereich Biologie/Chemie, Universität Osnabrück, D-49069, Osnabrück, Germany
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32
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Suvarna K, Bartiss A, Wong B. Mannitol-1-phosphate dehydrogenase from Cryptococcus neoformans is a zinc-containing long-chain alcohol/polyol dehydrogenase. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 10):2705-2713. [PMID: 11021946 DOI: 10.1099/00221287-146-10-2705] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cryptococcus neoformans, the causative agent of cryptococcosis, produces large amounts of mannitol in culture and in infected mammalian hosts. Although there is considerable indirect evidence that mannitol synthesis may be required for wild-type stress tolerance and virulence in C. neoformans, this hypothesis has not been tested directly. It has been proposed that mannitol-1-phosphate dehydrogenase (MPD) is required for fungal mannitol synthesis, but no MPD-deficient fungal mutants or cDNAs or genes encoding fungal MPDs have been described. Therefore, C. neoformans was purified from a 148 kDa homotetramer of 36 kDa subunits that catalysed the reaction mannitol1-phosphate+NAD--><--fructose 6-phosphate+NADH. Partial peptide sequences were used to isolate the corresponding cDNA and gene, and the deduced MPD protein was found to be homologous to the zinc-containing long-chain alcohol/polyol dehydrogenases. Lysates of Saccharomyces cerevisiae transformed with the cDNA of interest (but not vector-transformed controls) contained MPD catalytic activity. Lastly, Northern analyses demonstrated MPD mRNA in glucose- and mannitol-grown C. neoformans cells. Thus, MPD has been purified and characterized from C. neoformans, and the corresponding cDNA and gene (MPD1) cloned and sequenced. Availability of C. neoformans MPD1 should permit direct testing of the hypotheses that (i) MPD is required for mannitol biosynthesis and (ii) the ability to synthesize mannitol is essential for wild-type stress tolerance and virulence.
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Affiliation(s)
- Kalavat Suvarna
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA1
| | - Ann Bartiss
- Infectious Diseases Section, VA Connecticut Healthcare System, West Haven, CT, USA2
| | - Brian Wong
- Infectious Diseases Section, VA Connecticut Healthcare System, West Haven, CT, USA2
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA1
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33
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Wang H, Huang D, Lu R, Liu J, Qian Q, Peng X. Salt tolerance of transgenic rice (Oryza sativa L.) withmtlD gene andgutD gene. ACTA ACUST UNITED AC 2000. [DOI: 10.1007/bf02898987] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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34
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Shen B, Hohmann S, Jensen RG, Bohnert AH. Roles of sugar alcohols in osmotic stress adaptation. Replacement of glycerol by mannitol and sorbitol in yeast. PLANT PHYSIOLOGY 1999; 121:45-52. [PMID: 10482659 PMCID: PMC59388 DOI: 10.1104/pp.121.1.45] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/1999] [Accepted: 05/14/1999] [Indexed: 05/18/2023]
Abstract
For many organisms there is a correlation between increases of metabolites and osmotic stress tolerance, but the mechanisms that cause this protection are not clear. To understand the role of polyols, genes for bacterial mannitol-1-P dehydrogenase and apple sorbitol-6-P dehydrogenase were introduced into a Saccharomyces cerevisiae mutant deficient in glycerol synthesis. Sorbitol and mannitol provided some protection, but less than that generated by a similar concentration of glycerol generated by glycerol-3-P dehydrogenase (GPD1). Reduced protection by polyols suggested that glycerol had specific functions for which mannitol and sorbitol could not substitute, and that the absolute amount of the accumulating osmoticum might not be crucial. The retention of glycerol and mannitol/sorbitol, respectively, was a major difference. During salt stress, cells retained more of the six-carbon polyols than glycerol. We suggest that the loss of >98% of the glycerol synthesized could provide a safety valve that dissipates reducing power, while a similar high intracellular concentration of retained polyols would be less protective. To understand the role of glycerol in salt tolerance, salt-tolerant suppressor mutants were isolated from the glycerol-deficient strain. One mutant, sr13, partially suppressed the salt-sensitive phenotype of the glycerol-deficient line, probably due to a doubling of [K(+)] accumulating during stress. We compare these results to the "osmotic adjustment" concept typically applied to accumulating metabolites in plants. The accumulation of polyols may have dual functions: facilitating osmotic adjustment and supporting redox control.
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Affiliation(s)
- B Shen
- Department of Plant Sciences, The University of Arizona, Tucson 85721, USA
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35
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Bouvet OM, Pernoud S, Grimont PA. Temperature-dependent fermentation of D-sorbitol in Escherichia coli O157:H7. Appl Environ Microbiol 1999; 65:4245-57. [PMID: 10473445 PMCID: PMC99770 DOI: 10.1128/aem.65.9.4245-4257.1999] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The influence of growth temperature on the ability to ferment D-sorbitol was investigated in Escherichia coli O157:H7. It was found that O157:H7 strains have a temperature-sensitive sorbitol phenotype. D-Sorbitol transport and sorbitol-6-phosphate dehydrogenase activities were expressed in sorbitol-fermenting cells grown at 30 degrees C but only at a low level at 40 degrees C. Sorbitol-positive variants able to transport D-sorbitol were easily selected at 30 degrees C from culture of Sor(-) E. coli O157:H7 strains.
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Affiliation(s)
- O M Bouvet
- Unité des Entérobactéries, Unité INSERM 389, Institut Pasteur, 75724 Paris Cedex 15, France.
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36
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Rager MN, Binet MR, Bouvet OM. 31P and 13C nuclear magnetic resonance studies of metabolic pathways in Pasteurella multocida characterization of a new mannitol-producing metabolic pathway. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 263:695-701. [PMID: 10469132 DOI: 10.1046/j.1432-1327.1999.00540.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glucose metabolism of Pasteurella multocida was examined in resting cells in vivo using 13C NMR spectroscopy, in cell-free extracts in vitro using 31P NMR spectroscopy and using enzyme assays. The NMR data indicate that glucose is converted by the Embden-Meyerhof and pentose phosphate pathways. The P. multocida fructose 6-phosphate phosphotransferase activity (the key enzyme of the Embden-Meyerhof pathway) was similar to that of Escherichia coli. Nevertheless, and in contrast to that of E. coli, its activity was inhibited by alpha glycerophosphate. This inhibition is consistent with the very low fructose 6-phosphate phosphotransferase activity found in cell-free extracts of P. multocida using a spectrophotometric method. The dominant end products of glucose metabolism were mannitol, acetate and succinate. Under anaerobic conditions, P. multocida was able to constitutively produce mannitol from glucose, mannose, fructose, sucrose, glucose 6-phosphate and fructose 6-phosphate. We propose a new metabolic pathway in P. multocida where fructose 6-phosphate is reduced to mannitol 1-phosphate by fructose 6-phosphate reductase. Mannitol 1-phosphate produced is then converted to mannitol by mannitol 1-phosphatase.
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Affiliation(s)
- M N Rager
- Service de Résonance Magnétique Nucléaire UMR 7576, Ecole Nationale Supérieure de Chimie de Paris, France
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37
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Henstra SA, Tuinhof M, Duurkens RH, Robillard GT. The Bacillus stearothermophilus mannitol regulator, MtlR, of the phosphotransferase system. A DNA-binding protein, regulated by HPr and iicbmtl-dependent phosphorylation. J Biol Chem 1999; 274:4754-63. [PMID: 9988713 DOI: 10.1074/jbc.274.8.4754] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
D-Mannitol is taken up by Bacillus stearothermophilus and phosphorylated via a phosphoenolpyruvate-dependent phosphotransferase system (PTS). The genes involved in the mannitol uptake were recently cloned and sequenced. One of the genes codes for a putative transcriptional regulator, MtlR. The presence of a DNA binding helix-turn-helix motif and two antiterminator-like PTS regulation domains, suggest that MtlR is a DNA-binding protein, the activity of which can be regulated by phosphorylation by components of the PTS. To demonstrate DNA binding of MtlR to a region upstream of the mannitol promoter, by DNA footprinting, MtlR was overproduced and purified. EI, HPr, IIAmtl, and IICBmtl of B. stearothermophilus were purified and used to demonstrate that MtlR can be phosphorylated and regulated by HPr and IICBmtl, in vitro. Phosphorylation of MtlR by HPr increases the affinity of MtlR for its binding site, whereas phosphorylation by IICBmtl results in a reduction of this affinity. The differential effect of phosphorylation, by two different proteins, on the DNA binding properties of a bacterial transcriptional regulator has not, to our knowledge, been described before. Regulation of MtlR by two components of the PTS is an example of an elegant control system sensing both the presence of mannitol and the need to utilize this substrate.
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Affiliation(s)
- S A Henstra
- Departments of Biochemistry, the Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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38
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Brünker P, Altenbuchner J, Mattes R. Structure and function of the genes involved in mannitol, arabitol and glucitol utilization from Pseudomonas fluorescens DSM50106. Gene X 1998; 206:117-26. [PMID: 9461423 DOI: 10.1016/s0378-1119(97)00574-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A DNA fragment from Pseudomonas fluorescens DSM50106 containing the genes for the uptake and utilization of mannitol, arabitol and glucitol was cloned in Escherichia coli and sequenced. Seven open reading frames (mtlEFGKDYZ) were identified on the 10031 bp fragment. The deduced amino acid sequences of the first four open reading frames (mtlEFGK) revealed significant similarity to the components of the maltose transport system in E. coli and Salmonella typhimurium. The gene mtlD encoding a polyol dehydrogenase was located downstream of mtlK. The deduced proteins of the last two genes on the fragment showed a high similarity to a fructokinase from Vibrio alginolyticus (MtlZ) and a xylulose kinase from Streptomyces rubiginosus (MtlY), respectively. Both genes were expressed in E. coli. MtlZ phosphorylated fructose, glucose and glucitol whereas MtlY was highly specific for xylulose. Upstream of mtlE, a putative promoter/operator region was identified by promoter probe studies which was active in P. fluorescens but not in E. coli.
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Affiliation(s)
- P Brünker
- Institut für Industrielle Genetik, Universität Stuttgart, Germany
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39
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Chaturvedi V, Bartiss A, Wong B. Expression of bacterial mtlD in Saccharomyces cerevisiae results in mannitol synthesis and protects a glycerol-defective mutant from high-salt and oxidative stress. J Bacteriol 1997; 179:157-62. [PMID: 8981993 PMCID: PMC178674 DOI: 10.1128/jb.179.1.157-162.1997] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Polyols, or polyhydroxy alcohols, are produced by many fungi. Saccharomyces cerevisiae produces large amounts of glycerol, and several fungi that cause serious human infections produce D-arabinitol and mannitol. Glycerol functions as an intracellular osmolyte in S. cerevisiae, but the functions of D-arabinitol and mannitol in pathogenic fungi are not yet known. To investigate the functions of mannitol, we constructed a new mannitol biosynthetic pathway in S. cerevisiae. S. cerevisiae transformed with multicopy plasmids encoding the mannitol-1-phosphate dehydrogenase of Escherichia coli produced mannitol, whereas S. cerevisiae transformed with control plasmids did not. Although mannitol production had no obvious phenotypic effects in wild-type S. cerevisiae, it restored the ability of a glycerol-defective, osmosensitive osg1-1 mutant to grow in the presence of high NaCl concentrations. Moreover, osg1-1 mutants producing mannitol were more resistant to killing by oxidants produced by a cell-free H2O2-FeSO4-NaI system than were controls. These results indicate that mannitol can (i) function as an intracellular osmolyte in S. cerevisiae, (ii) substitute for glycerol as the principal intracellular osmolyte in S. cerevisiae, and (iii) protect S. cerevisiae from oxidative damage by scavenging toxic oxygen intermediates.
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Affiliation(s)
- V Chaturvedi
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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40
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Wagner E, Marcandier S, Egeter O, Deutscher J, Götz F, Brückner R. Glucose kinase-dependent catabolite repression in Staphylococcus xylosus. J Bacteriol 1995; 177:6144-52. [PMID: 7592379 PMCID: PMC177454 DOI: 10.1128/jb.177.21.6144-6152.1995] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
By transposon Tn917 mutagenesis, 16 mutants of Staphylococcus xylosus were isolated that showed higher levels of beta-galactosidase activity in the presence of glucose than the wild-type strain. The transposons were found to reside in three adjacent locations in the genome of S. xylosus. The nucleotide sequence of the chromosomal fragment affected by the Tn917 insertions yielded an open reading frame encoding a protein with a size of 328 amino acids with a high level of similarity to glucose kinase from Streptomyces coelicolor. Weaker similarity was also found to bacterial fructokinases and xylose repressors of gram-positive bacteria. The gene was designated glkA. Immediately downstream of glkA, two open reading frames were present whose deduced gene products showed no obvious similarity to known proteins. Measurements of catabolic enzyme activities in the mutant strains grown in the presence or absence of sugars established the pleiotropic nature of the mutations. Besides beta-galactosidase activity, which had been used to detect the mutants, six other tested enzymes were partially relieved from repression by glucose. Reduction of fructose-mediated catabolite repression was observed for some of the enzyme activities. Glucose transport and ATP-dependent phosphorylation of HPr, the phosphocarrier of the phosphoenolpyruvate:carbohydrate phosphotransferase system involved in catabolite repression in gram-positive bacteria, were not affected. The cloned glkA gene fully restored catabolite repression in the mutant strains in trans. Loss of GlkA function is thus responsible for the partial relief from catabolite repression. Glucose kinase activity in the mutants reached about 75% of the wild-type level, indicating the presence of another enzyme in S. xylosus. However, the cloned gene complemented an Escherichia coli strain in glucose kinase. Therefore, the glkA gene encodes a glucose kinase that participates in catabolite repression in S. xylosus.
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Affiliation(s)
- E Wagner
- Mikrobielle Genetik, Universität Tübingen, Germany
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41
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Kalfas S, Takahashi N, Yamada T. Initial catabolism of sorbitol in Actinomyces naeslundii and Actinomyces viscosus. ORAL MICROBIOLOGY AND IMMUNOLOGY 1994; 9:372-5. [PMID: 7870473 DOI: 10.1111/j.1399-302x.1994.tb00288.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The initial steps of sorbitol catabolism were studied in 4 strains of Actinomyces naeslundii and Actinomyces viscosus that had been isolated from human dental plaque. Cell-free extracts were prepared from cells grown in the presence of either sorbitol, xylitol or glucose. The extracts from all strains grown on sorbitol had nicotinamide adenine dinucleotide-linked dehydrogenase activities for sorbitol and xylitol and reduced nicotinamide adenine dinucleotide-linked reductase activities for fructose and xylulose. Two of the strains also exhibited these activities when grown in the presence of xylitol, and all glucose-grown cells lacked them. The results indicate that sorbitol metabolism in oral actinomyces involve oxidation of sorbitol to fructose by an inducible enzyme, nicotinamide adenine dinucleotide-linked sorbitol dehydrogenase. This step is followed by the phosphorylation of fructose with guanosine triphosphate as a main phosphoryl donor. Thus, the initial catabolic pathway of sorbitol in A. naeslundii and A. viscosus is different from those described for other oral bacteria.
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Affiliation(s)
- S Kalfas
- Department of Oral Microbiology, Centre for Oral Health Sciences, University of Lund, Malmö, Sweden
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42
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Deutscher J, Reizer J, Fischer C, Galinier A, Saier MH, Steinmetz M. Loss of protein kinase-catalyzed phosphorylation of HPr, a phosphocarrier protein of the phosphotransferase system, by mutation of the ptsH gene confers catabolite repression resistance to several catabolic genes of Bacillus subtilis. J Bacteriol 1994; 176:3336-44. [PMID: 8195089 PMCID: PMC205505 DOI: 10.1128/jb.176.11.3336-3344.1994] [Citation(s) in RCA: 169] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In gram-positive bacteria, HPr, a phosphocarrier protein of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), is phosphorylated by an ATP-dependent, metabolite-activated protein kinase on seryl residue 46. In a Bacillus subtilis mutant strain in which Ser-46 of HPr was replaced with a nonphosphorylatable alanyl residue (ptsH1 mutation), synthesis of gluconate kinase, glucitol dehydrogenase, mannitol-1-P dehydrogenase and the mannitol-specific PTS permease was completely relieved from repression by glucose, fructose, or mannitol, whereas synthesis of inositol dehydrogenase was partially relieved from catabolite repression and synthesis of alpha-glucosidase and glycerol kinase was still subject to catabolite repression. When the S46A mutation in HPr was reverted to give S46 wild-type HPr, expression of gluconate kinase and glucitol dehydrogenase regained full sensitivity to repression by PTS sugars. These results suggest that phosphorylation of HPr at Ser-46 is directly or indirectly involved in catabolite repression. A strain deleted for the ptsGHI genes was transformed with plasmids expressing either the wild-type ptsH gene or various S46 mutant ptsH genes (S46A or S46D). Expression of the gene encoding S46D HPr, having a structure similar to that of P-ser-HPr according to nuclear magnetic resonance data, caused significant reduction of gluconate kinase activity, whereas expression of the genes encoding wild-type or S46A HPr had no effect on this enzyme activity. When the promoterless lacZ gene was put under the control of the gnt promoter and was subsequently incorporated into the amyE gene on the B. subtilis chromosome, expression of beta-galactosidase was inducible by gluconate and repressed by glucose. However, we observed no repression of beta-galactosidase activity in a strain carrying the ptsH1 mutation. Additionally, we investigated a ccpA mutant strain and observed that all of the enzymes which we found to be relieved from carbon catabolite repression in the ptsH1 mutant strain were also insensitive to catabolite repression in the ccpA mutant. Enzymes that were repressed in the ptsH1 mutant were also repressed in the ccpA mutant.
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Affiliation(s)
- J Deutscher
- Max Planck Institute for Molecular Physiology, Dortmund, Germany
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43
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Abstract
The mannitol operon of Escherichia coli, encoding the mannitol-specific enzyme II of the phosphotransferase system (Mt1A) and mannitol phosphate dehydrogenase (Mt1D), is here shown to contain a single additional downstream open reading frame which encodes the mannitol repressor (Mt1R). Mt1R contains 195 amino acids and has a calculated molecular weight of 21,990 and a calculated pI of 4.5. It is homologous to the product of an open reading frame (URF2D) upstream of the E. coli gapB gene but represents a novel type of transcriptional regulatory protein.
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Affiliation(s)
- R M Figge
- Department of Biology, University of California at San Diego, La Jolla 92093-0116
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44
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Svensäter G, Edwardsson S, Kalfas S. Purification and properties of sorbitol-6-phosphate dehydrogenase from oral streptococci. ORAL MICROBIOLOGY AND IMMUNOLOGY 1992; 7:148-54. [PMID: 1408350 DOI: 10.1111/j.1399-302x.1992.tb00528.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The activity of sorbitol-6-phosphate (S6P) dehydrogenase (S6PDH) and the sorbitol transport system were studied in strains of the oral streptococci Streptococcus gordonii, Streptococcus mitis, Streptococcus sanguis and Streptococcus mutans. Genetically transformed (to ferment sorbitol) strains and their DNA donors were included. S6PDH was purified by anion exchange chromatography and gel filtration. The purity of the enzyme was confirmed by polyacrylamide gel electrophoresis. The purified enzyme from all the strains exhibited Michaelis-Menton saturation kinetics. The Km values for nicotinamide-adenine dinucleotide (NAD) and S6P ranged between 0.03 and 0.21 mM and 0.07 and 0.20 mM respectively. The relative molecular weights of the native enzyme were 229,000 for one donor-transformant pair (S. sanguis and S. gordonii), 107,000 for the other pair (S. mitis and S. gordonii) and 129,000 for S. mutans. The molecular weights of the S6PDH subunits ranged from 26,000 to 28,000. The pH optima (greater than 8.5) and the amino acid composition (15 amino acids examined) were similar for the S6PDH from the different strains. However, the chromatographic and electrophoretic patterns as well as the Km values for NAD and S6P were the same only between the S6PDHs from the strains within each donor-transformant pair. Purified S6PDH from S. mutans also exhibited low mannitol-1-phosphate dehydrogenase activity. Sorbitol-grown decryptified cells of all the strains phosphorylated sorbitol in the presence of phosphoenolpyruvate but not in the presence of adenosine triphosphate (ATP). ATP-mediated phosphorylation of glucose was observed with the same strains when grown on glucose. No evidence for a non-phosphotransferase transport system was found for sorbitol in any of the strains.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G Svensäter
- Centre for Oral Health Sciences, University of Lund, Malmö, Sweden
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45
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Wöhrl BM, Lengeler JW. Cloning and physical mapping of the sor genes for L-sorbose transport and metabolism from Klebsiella pneumoniae. Mol Microbiol 1990; 4:1557-65. [PMID: 2287279 DOI: 10.1111/j.1365-2958.1990.tb02067.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The sor genes of Klebsiella pneumoniae KAY2026, which enable the bacterium to metabolize the ketose L-sorbose, have been cloned on an 8.3kb DNA fragment into the multicopy plasmid, pACYC184. The genes were mapped by restriction analysis, by deletion mapping and by insertion mutagenesis with Tn1725. The corresponding gene products were identified by the maxicell technique. The structural genes sorD, sorA and sorE code for a D-glucitol-6-P dehydrogenase (27 kilodalton (kD)), an Enzymell (EllSor) activity specific for L-sorbose and an L-sorbose-1-P reductase (45kD). Besides these genes for known functions, three additional genes were discovered: sorC, coding for a transcriptional 40kD regulatory protein, and sorF and sorB, coding for two proteins of 14kD and 19kD, respectively, involved in transport. The genes form an operon (gene order sorCpCDFBAE) and are inducible by L-sorbose.
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Affiliation(s)
- B M Wöhrl
- Max-Planck-Institut für Molekulare Genetik, Berlin, FRG
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46
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47
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Teschner W, Serre MC, Garel JR. Enzymatic properties, renaturation and metabolic role of mannitol-1-phosphate dehydrogenase from Escherichia coli. Biochimie 1990; 72:33-40. [PMID: 2111176 DOI: 10.1016/0300-9084(90)90170-l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Enzymatic properties, renaturation and metabolic role of mannitol-1-phosphate dehydrogenase from Escherichia coli. D-mannitol-1-phosphate dehydrogenase was purified to homogeneity from Escherichia coli, and its physicochemical and enzymatic properties were investigated. The molecular weight of the polypeptide chain is 45,000 as determined by polyacrylamide gel electrophoresis in denaturing conditions. High performance size exclusion chromatography gives an apparent molecular weight of 47,000 for the native enzyme, showing that D-mannitol-1-phosphate dehydrogenase is a monomeric NAD-dependent dehydrogenase. D-mannitol-1-phosphate dehydrogenase is rapidly denatured by 6 M guanidine hydrochloride. Non-superimposable transition curves for the loss of activity and the changes in fluorescence suggest the existence of a partially folded inactive intermediate. The protein can be fully renatured after complete unfolding, and the regain of both native fluorescence and activity occurs rapidly within a few seconds at pH 7.5 and 20 degrees C. Such a high rate of reactivation is unusual for a protein of this size. D-mannitol-1-phosphate dehydrogenase is specific for mannitol-1-phosphate (or fructose-6-phosphate) as a substrate and NAD+ (or NADH) as a cofactor. Zinc is not required for the activity. The affinity of D-mannitol-1-phosphate dehydrogenase for the reduced or oxidized form of its substrate or cofactor remains constant with pH. The affinity for NADH is 20-fold higher than for NAD+. The forward and reverse catalytic rate constants of the reaction: mannitol-1-phosphate + NAD+ in equilibrium fructose-6-phosphate + NADH have different pH dependences. The oxidation of mannitol-1-phosphate has an optimum pH of 9.5, while the reduction of fructose-6-phosphate has its maximum rate at pH 7.0. At pH values around neutrality the maximum rate of reduction of fructose-6-phosphate is much higher than that of oxidation of mannitol-1-phosphate. The enzymatic properties of isolated D-mannitol-1-phosphate dehydrogenase are discussed in relation to the role of this enzyme in the intracellular metabolism.
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Affiliation(s)
- W Teschner
- Laboratoire d'Enzymologie Centre, National de la Recherche Scientifique, Gif-Sur-Yvette, France
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48
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Yamada M, Yamada Y, Saier MH. Nucleotide sequence and expression of the gutQ gene within the glucitol operon of Escherichia coli. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 1990; 1:141-5. [PMID: 2134185 DOI: 10.3109/10425179009016042] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The glucitol operon in Escherichia coli is known to consist of five structural genes with the order: gut O P A B D M R. We have sequenced downstream from gutR and have identified an open reading frame encoding a water-soluble protein (223 amino acids; molecular weight = 23,562) with a putative ATP binding site. Expression of this protein in a maxicell system has been demonstrated. A repetitive extragenic palindromic (REP) sequence capable of forming stem-loop structures follows gutQ in the downstream, presumptive intercistronic region. The function of the Gut Q protein is not known.
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Affiliation(s)
- M Yamada
- Department of Biology, University of California, San Diego, La Jolla 92093
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49
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Yamada M, Saier MH. Positive and negative regulators for glucitol (gut) operon expression in Escherichia coli. J Mol Biol 1988; 203:569-83. [PMID: 3062173 DOI: 10.1016/0022-2836(88)90193-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Expression of the glucitol (gut) operon in Escherichia coli is regulated by an unusual, complex system which consists of an activator (encoded by the gutM gene) and a repressor (encoded by the gutR gene) in addition to the cAMP-CRP complex (CRP, cAMP receptor protein). The activator and repressor are predicted to possess 119 (Mr = 12,955) and 257 (Mr = 28,240) aminoacyl residues, respectively, as deduced from the nucleotide sequences of their structural genes. Both of the genes encoding the two regulators are located downstream from the other known gut structural genes. Reverse transcriptase mapping revealed that the gutM gene is a promoter-distal constituent of the gut operon. The gutR gene has its own promoter, but expression of this gene is primarily due to readthrough from the gut operon operator-promoter. Thus, the gut operon consists of at least five structural genes and has the following gene order: gutOPABDMR. Interestingly, synthesis of the mRNA, which initiates at the promoter specific to the gutR gene, occurs within the gutM gene. Expressional control of the gut operon appears to occur as a consequence of the antagonistic action of the products of the autogenously regulated gutM and gutR genes. An additional cistron of the gut operon, of unknown function, may follow the gutR gene.
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Affiliation(s)
- M Yamada
- Department of Biology, John Muir College, University of California at San Diego, La Jolla 92093
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50
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Abstract
The nucleotide sequence of the known portions of the mannitol operon in Escherichia coli (mtlOPAD) has been determined. Both the operator-promoter region and the intercistronic region between the mtlA and mtlD genes (encoding the mannitol-specific Enzyme II of the phosphotransferase system and mannitol-1-phosphate dehydrogenase, respectively) show parallels with corresponding regions of the glucitol (gut) operon, but neither the mtlA nor the mtlD gene products show obvious homology with the corresponding gene products of the glucitol operon. Five potential cyclic AMP receptor protein binding sites were identified in the mtlOP region, all showing near identity with the consensus sequence. Four regions of dyad symmetry (four to seven bases in length), serving as potential repressor binding sites, overlap with the potential cyclic AMP receptor protein binding sites. Repetitive extragenic palindromic (REP) sequences, forming stem-loop structures in the intercistronic region between mtlA and mtlD and following the mtlD gene were identified. Probable terminator sequences were not found in any of these three regulatory regions. Mannitol-1-phosphate dehydrogenase exhibits two overlapping, potential NAD+ binding sites near the N-terminus of the protein. Computer techniques were used to analyse the mtlD gene and its product.
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Affiliation(s)
- T Davis
- Department of Biology, University of California at San Diego, La Jolla 92093
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