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Wang SY, Zhang N, Teng ZJ, Wang XD, Todd JD, Zhang YZ, Cao HY, Li CY. A new dimethylsulfoniopropionate lyase of the cupin superfamily in marine bacteria. Environ Microbiol 2023. [PMID: 36808192 DOI: 10.1111/1462-2920.16355] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
Dimethylsulfoniopropionate (DMSP) is a marine organosulfur compound with important roles in stress protection, marine biogeochemical cycling, chemical signalling and atmospheric chemistry. Diverse marine microorganisms catabolize DMSP via DMSP lyases to generate the climate-cooling gas and info-chemical dimethyl sulphide. Abundant marine heterotrophs of the Roseobacter group (MRG) are well known for their ability to catabolize DMSP via diverse DMSP lyases. Here, a new DMSP lyase DddU within the MRG strain Amylibacter cionae H-12 and other related bacteria was identified. DddU is a cupin superfamily DMSP lyase like DddL, DddQ, DddW, DddK and DddY, but shares <15% amino acid sequence identity with these enzymes. Moreover, DddU proteins forms a distinct clade from these other cupin-containing DMSP lyases. Structural prediction and mutational analyses suggested that a conserved tyrosine residue is the key catalytic amino acid residue in DddU. Bioinformatic analysis indicated that the dddU gene, mainly from Alphaproteobacteria, is widely distributed in the Atlantic, Pacific, Indian and polar oceans. For reference, dddU is less abundant than dddP, dddQ and dddK, but much more frequent than dddW, dddY and dddL in marine environments. This study broadens our knowledge on the diversity of DMSP lyases, and enhances our understanding of marine DMSP biotransformation.
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Affiliation(s)
- Shu-Yan Wang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China.,State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Nan Zhang
- School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
| | - Zhao-Jie Teng
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Xiao-Di Wang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Jonathan D Todd
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Yu-Zhong Zhang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China.,State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Hai-Yan Cao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China.,State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Chun-Yang Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
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Shaw DK, Sekar J, Ramalingam PV. Recent insights into oceanic dimethylsulfoniopropionate biosynthesis and catabolism. Environ Microbiol 2022; 24:2669-2700. [PMID: 35611751 DOI: 10.1111/1462-2920.16045] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 11/29/2022]
Abstract
Dimethylsulfoniopropionate (DMSP), a globally important organosulfur compound is produced in prodigious amounts (2.0 Pg sulfur) annually in the marine environment by phytoplankton, macroalgae, heterotrophic bacteria, some corals and certain higher plants. It is an important marine osmolyte and a major precursor molecule for the production of climate-active volatile gas dimethyl sulfide (DMS). DMSP synthesis take place via three pathways: a transamination 'pathway-' in some marine bacteria and algae, a Met-methylation 'pathway-' in angiosperms and bacteria and a decarboxylation 'pathway-' in the dinoflagellate, Crypthecodinium. The enzymes DSYB and TpMMT are involved in the DMSP biosynthesis in eukaryotes while marine heterotrophic bacteria engage key enzymes such as DsyB and MmtN. Several marine bacterial communities import DMSP and degrade it via cleavage or demethylation pathways or oxidation pathway, thereby generating DMS, methanethiol, and dimethylsulfoxonium propionate, respectively. DMSP is cleaved through diverse DMSP lyase enzymes in bacteria and via Alma1 enzyme in phytoplankton. The demethylation pathway involves four different enzymes, namely DmdA, DmdB, DmdC and DmdD/AcuH. However, enzymes involved in the oxidation pathway have not been yet identified. We reviewed the recent advances on the synthesis and catabolism of DMSP and enzymes that are involved in these processes.
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Affiliation(s)
- Deepak Kumar Shaw
- Microbiology Lab, Department of Biotechnology, M. S. Swaminathan Research Foundation, Taramani, Chennai, 600113, Tamil Nadu, India
| | - Jegan Sekar
- Microbiology Lab, Department of Biotechnology, M. S. Swaminathan Research Foundation, Taramani, Chennai, 600113, Tamil Nadu, India
| | - Prabavathy Vaiyapuri Ramalingam
- Microbiology Lab, Department of Biotechnology, M. S. Swaminathan Research Foundation, Taramani, Chennai, 600113, Tamil Nadu, India
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The organosulfur compound dimethylsulfoniopropionate (DMSP) is utilized as an osmoprotectant by Vibrio species. Appl Environ Microbiol 2021; 87:AEM.02235-20. [PMID: 33355097 PMCID: PMC8090876 DOI: 10.1128/aem.02235-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dimethylsulfoniopropionate (DMSP), a key component of the global geochemical sulfur cycle, is a secondary metabolite produced in large quantities by marine phytoplankton and utilized as an osmoprotectant, thermoprotectant and antioxidant. Marine bacteria can use two pathways to degrade and catabolize DMSP, a demethylation pathway and a cleavage pathway that produces the climate active gas dimethylsulfide (DMS). Whether marine bacteria can also accumulate DMSP as an osmoprotectant to maintain the turgor pressure of the cell in response to changes in external osmolarity has received little attention. The marine halophile Vibrio parahaemolyticus, contains at least six osmolyte transporters, four betaine carnitine choline transport (BCCT) carriers BccT1-BccT4 and two ABC-family ProU transporters. In this study, we showed that DMSP is used as an osmoprotectant by V. parahaemolyticus and several other Vibrio species including V. cholerae and V. vulnificus Using a V. parahaemolyticus proU double mutant, we demonstrated that these ABC transporters are not required for DMSP uptake. However, a bccT null mutant lacking all four BCCTs had a growth defect compared to wild type in high salinity media supplemented with DMSP. Using mutants possessing only one functional BCCT in growth pattern assays, we identified two BCCT-family transporters, BccT1 and BccT2, which are carriers of DMSP. The only V. parahaemolyticus BccT homolog that V. cholerae and V. vulnificus possess is BccT3 and functional complementation in Escherichia coli MKH13 showed V. cholerae VcBccT3 could transport DMSP. In V. vulnificus strains, we identified and characterized an additional BCCT family transporter, which we named BccT5 that was also a carrier for DMSP.Importance DMSP is present in the marine environment, produced in large quantities by marine phytoplankton as an osmoprotectant, and is an important component of the global geochemical sulfur cycle. This algal osmolyte has not been previously investigated for its role in marine heterotrophic bacterial osmotic stress response. Vibrionaceae are marine species, many of which are halophiles exemplified by V. parahaemolyticus, a species that possesses at least six transporters for the uptake of osmolytes. Here, we demonstrated that V. parahaemolyticus and other Vibrio species can accumulate DMSP as an osmoprotectant and show that several BCCT family transporters uptake DMSP. These studies suggest that DMSP is a significant bacterial osmoprotectant, which may be important for understanding the fate of DMSP in the environment. DMSP is produced and present in coral mucus and Vibrio species form part of the microbial communities associated with them. The function of DMSP in these interactions is unclear, but could be an important driver for these associations allowing Vibrio proliferation. This work suggests that DMSP likely has an important role in heterotrophic bacteria ecology than previously appreciated.
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Gregory GJ, Boyd EF. Stressed out: Bacterial response to high salinity using compatible solute biosynthesis and uptake systems, lessons from Vibrionaceae. Comput Struct Biotechnol J 2021; 19:1014-1027. [PMID: 33613867 PMCID: PMC7876524 DOI: 10.1016/j.csbj.2021.01.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 12/19/2022] Open
Abstract
Bacteria have evolved mechanisms that allow them to adapt to changes in osmolarity and some species have adapted to live optimally in high salinity environments such as in the marine ecosystem. Most bacteria that live in high salinity do so by the biosynthesis and/or uptake of compatible solutes, small organic molecules that maintain the turgor pressure of the cell. Osmotic stress response mechanisms and their regulation among marine heterotrophic bacteria are poorly understood. In this review, we discuss what is known about compatible solute metabolism and transport and new insights gained from studying marine bacteria belonging to the family Vibrionaceae.
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Affiliation(s)
| | - E. Fidelma Boyd
- Corresponding author at: Department of Biological Sciences, 341 Wolf Hall, University of Delaware, Newark, DE 19716, United States.
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5
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Zhang XH, Liu J, Liu J, Yang G, Xue CX, Curson ARJ, Todd JD. Biogenic production of DMSP and its degradation to DMS-their roles in the global sulfur cycle. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1296-1319. [PMID: 31231779 DOI: 10.1007/s11427-018-9524-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/16/2019] [Indexed: 01/08/2023]
Abstract
Dimethyl sulfide (DMS) is the most abundant form of volatile sulfur in Earth's oceans, and is mainly produced by the enzymatic clevage of dimethylsulfoniopropionate (DMSP). DMS and DMSP play important roles in driving the global sulfur cycle and may affect climate. DMSP is proposed to serve as an osmolyte, a grazing deterrent, a signaling molecule, an antioxidant, a cryoprotectant and/or as a sink for excess sulfur. It was long believed that only marine eukaryotes such as phytoplankton produce DMSP. However, we recently discovered that marine heterotrophic bacteria can also produce DMSP, making them a potentially important source of DMSP. At present, one prokaryotic and two eukaryotic DMSP synthesis enzymes have been identified. Marine heterotrophic bacteria are likely the major degraders of DMSP, using two known pathways: demethylation and cleavage. Many phytoplankton and some fungi can also cleave DMSP. So far seven different prokaryotic and one eukaryotic DMSP lyases have been identified. This review describes the global distribution pattern of DMSP and DMS, the known genes for biosynthesis and cleavage of DMSP, and the physiological and ecological functions of these important organosulfur molecules, which will improve understanding of the mechanisms of DMSP and DMS production and their roles in the environment.
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Affiliation(s)
- Xiao-Hua Zhang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
| | - Ji Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Jingli Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Guipeng Yang
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, 266071, China
| | - Chun-Xu Xue
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Andrew R J Curson
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Jonathan D Todd
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
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Abstract
The organosulfur metabolite dimethylsulfoniopropionate (DMSP) and its enzymatic breakdown product dimethyl sulfide (DMS) have important implications in the global sulfur cycle and in marine microbial food webs. Enormous amounts of DMSP are produced in marine environments where microbial communities import and catabolize it via either the demethylation or the cleavage pathways. The enzymes that cleave DMSP are termed "DMSP lyases" and generate acrylate or hydroxypropionate, and ~107tons of DMS annually. An important environmental factor affecting DMS generation by the DMSP lyases is the availability of metal ions as these enzymes use various cofactors for catalysis. This chapter summarizes advances on bacterial DMSP catabolism, with an emphasis on various biochemical methods employed for the isolation and characterization of bacterial DMSP lyases. Strategies are presented for the purification of DMSP lyases expressed in bacterial cells. Specific conditions for the efficient isolation of apoproteins in Escherichia coli are detailed. DMSP cleavage is effectively inferred, utilizing the described HPLC-based acrylate detection assay. Finally, substrate and metal binding interactions are examined using fluorescence and UV-visible assays. Together, these methods are rapid and well suited for the biochemical and structural characterization of DMSP lyases and in the assessment of uncharacterized DMSP catabolic enzymes, and new metalloenzymes in general.
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Structure-Function Analysis Indicates that an Active-Site Water Molecule Participates in Dimethylsulfoniopropionate Cleavage by DddK. Appl Environ Microbiol 2019; 85:AEM.03127-18. [PMID: 30770407 DOI: 10.1128/aem.03127-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 02/13/2019] [Indexed: 11/20/2022] Open
Abstract
The osmolyte dimethylsulfoniopropionate (DMSP) is produced in petagram quantities in marine environments and has important roles in global sulfur and carbon cycling. Many marine microorganisms catabolize DMSP via DMSP lyases, generating the climate-active gas dimethyl sulfide (DMS). DMS oxidation products participate in forming cloud condensation nuclei and, thus, may influence weather and climate. SAR11 bacteria are the most abundant marine heterotrophic bacteria; many of them contain the DMSP lyase DddK, and their dddK transcripts are relatively abundant in seawater. In a recently described catalytic mechanism for DddK, Tyr64 is predicted to act as the catalytic base initiating the β-elimination reaction of DMSP. Tyr64 was proposed to be deprotonated by coordination to the metal cofactor or its neighboring His96. To further probe this mechanism, we purified and characterized the DddK protein from Pelagibacter ubique strain HTCC1062 and determined the crystal structures of wild-type DddK and its Y64A and Y122A mutants (bearing a change of Y to A at position 64 or 122, respectively), where the Y122A mutant is complexed with DMSP. The structural and mutational analyses largely support the catalytic role of Tyr64, but not the method of its deprotonation. Our data indicate that an active water molecule in the active site of DddK plays an important role in the deprotonation of Tyr64 and that this is far more likely than coordination to the metal or His96. Sequence alignment and phylogenetic analysis suggest that the proposed catalytic mechanism of DddK has universal significance. Our results provide new mechanistic insights into DddK and enrich our understanding of DMS generation by SAR11 bacteria.IMPORTANCE The climate-active gas dimethyl sulfide (DMS) plays an important role in global sulfur cycling and atmospheric chemistry. DMS is mainly produced through the bacterial cleavage of marine dimethylsulfoniopropionate (DMSP). When released into the atmosphere from the oceans, DMS can be photochemically oxidized into DMSO or sulfate aerosols, which form cloud condensation nuclei that influence the reflectivity of clouds and, thereby, global temperature. SAR11 bacteria are the most abundant marine heterotrophic bacteria, and many of them contain DMSP lyase DddK to cleave DMSP, generating DMS. In this study, based on structural analyses and mutational assays, we revealed the catalytic mechanism of DddK, which has universal significance in SAR11 bacteria. This study provides new insights into the catalytic mechanism of DddK, leading to a better understanding of how SAR11 bacteria generate DMS.
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Chen Y, Schäfer H. Towards a systematic understanding of structure-function relationship of dimethylsulfoniopropionate-catabolizing enzymes. Mol Microbiol 2019; 111:1399-1403. [PMID: 30802340 DOI: 10.1111/mmi.14230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2019] [Indexed: 11/28/2022]
Abstract
Each year, several million tons of dimethylsulfoniopropionate (DMSP) are produced by marine phytoplankton and bacteria as an important osmolyte to regulate their cellular osmosis. Microbial breakdown of DMSP to the volatile gas dimethylsulfide (DMS) plays an important role in global biogeochemical cycles of the sulphur element between land and the sea. Understanding the enzymes involved in the transformation of DMSP and DMS holds the key to a better understanding of oceanic DMSP cycles. Recent work by Shao et al. (2019) has resolved the crystal structure of two important enzymes, DmdB and DmdC, involved in DMSP transformation through the demethylation pathway. Their work represents an important step towards a systematic understanding of the structure-function relationships of DMSP-catabolizing enzymes in marine microbes.
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Affiliation(s)
- Yin Chen
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Hendrik Schäfer
- School of Life Sciences, University of Warwick, Coventry, UK
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9
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Lei L, Alcolombri U, Tawfik DS. Biochemical Profiling of DMSP Lyases. Methods Enzymol 2018; 605:269-289. [PMID: 29909827 DOI: 10.1016/bs.mie.2018.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dimethyl sulfide (DMS) is released at rates of >107 tons annually and plays a key role in the oceanic sulfur cycle and ecology. Marine bacteria, algae, and possibly other organisms release DMS via cleavage of dimethylsulfoniopropionate (DMSP). DMSP lyases have been identified in various organisms, including bacteria, coral, and algae, thus comprising a range of gene families putatively assigned as DMSP lyases. Metagenomics may therefore provide insight regarding the presence of DMSP lyases in various marine environments, thereby promoting a better understanding of global DMS emission. However, gene counts, and even mRNA levels, do not necessarily reflect the level of DMSP cleavage activity in a given environmental sample, especially because some of the families assigned as DMSP lyases may merely exhibit promiscuous lyase activity. Here, we describe a range of biochemical profiling methods that can assign an observed DMSP lysis activity to a specific gene family. These methods include selective inhibitors and DMSP substrate analogues. Combined with genomics and metagenomics, biochemical profiling may enable a more reliable identification of the origins of DMS release in specific organisms and in crude environmental samples.
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Affiliation(s)
- Lei Lei
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Uria Alcolombri
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Dan S Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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Li CY, Zhang D, Chen XL, Wang P, Shi WL, Li PY, Zhang XY, Qin QL, Todd JD, Zhang YZ. Mechanistic Insights into Dimethylsulfoniopropionate Lyase DddY, a New Member of the Cupin Superfamily. J Mol Biol 2017; 429:3850-3862. [DOI: 10.1016/j.jmb.2017.10.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/08/2017] [Accepted: 10/19/2017] [Indexed: 12/28/2022]
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Bullock HA, Luo H, Whitman WB. Evolution of Dimethylsulfoniopropionate Metabolism in Marine Phytoplankton and Bacteria. Front Microbiol 2017; 8:637. [PMID: 28469605 PMCID: PMC5395565 DOI: 10.3389/fmicb.2017.00637] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 03/28/2017] [Indexed: 11/13/2022] Open
Abstract
The elucidation of the pathways for dimethylsulfoniopropionate (DMSP) synthesis and metabolism and the ecological impact of DMSP have been studied for nearly 70 years. Much of this interest stems from the fact that DMSP metabolism produces the climatically active gas dimethyl sulfide (DMS), the primary natural source of sulfur to the atmosphere. DMSP plays many important roles for marine life, including use as an osmolyte, antioxidant, predator deterrent, and cryoprotectant for phytoplankton and as a reduced carbon and sulfur source for marine bacteria. DMSP is hypothesized to have become abundant in oceans approximately 250 million years ago with the diversification of the strong DMSP producers, the dinoflagellates. This event coincides with the first genome expansion of the Roseobacter clade, known DMSP degraders. Structural and mechanistic studies of the enzymes of the bacterial DMSP demethylation and cleavage pathways suggest that exposure to DMSP led to the recruitment of enzymes from preexisting metabolic pathways. In some cases, such as DmdA, DmdD, and DddP, these enzymes appear to have evolved to become more specific for DMSP metabolism. By contrast, many of the other enzymes, DmdB, DmdC, and the acrylate utilization hydratase AcuH, have maintained broad functionality and substrate specificities, allowing them to carry out a range of reactions within the cell. This review will cover the experimental evidence supporting the hypothesis that, as DMSP became more readily available in the marine environment, marine bacteria adapted enzymes already encoded in their genomes to utilize this new compound.
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Affiliation(s)
- Hannah A Bullock
- Department of Microbiology, University of Georgia, AthensGA, USA
| | - Haiwei Luo
- School of Life Sciences, The Chinese University of Hong KongHong Kong, Hong Kong
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Enzymology of Microbial Dimethylsulfoniopropionate Catabolism. STRUCTURAL AND MECHANISTIC ENZYMOLOGY 2017; 109:195-222. [DOI: 10.1016/bs.apcsb.2017.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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14
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Brummett AE, Dey M. New Mechanistic Insight from Substrate- and Product-Bound Structures of the Metal-Dependent Dimethylsulfoniopropionate Lyase DddQ. Biochemistry 2016; 55:6162-6174. [PMID: 27755868 DOI: 10.1021/acs.biochem.6b00585] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The marine microbial catabolism of dimethylsulfoniopropionate (DMSP) by the lyase pathway liberates ∼300 million tons of dimethyl sulfide (DMS) per year, which plays a major role in the biogeochemical cycling of sulfur. Recent biochemical and structural studies of some DMSP lyases, including DddQ, reveal the importance of divalent transition metal ions in assisting DMSP cleavage. While DddQ is believed to be zinc-dependent primarily on the basis of structural studies, excess zinc inhibits the enzyme. We examine the importance of iron in regulating the DMSP β-elimination reaction catalyzed by DddQ as our as-isolated purple-colored enzyme possesses ∼0.5 Fe/subunit. The UV-visible spectrum exhibited a feature at 550 nm, consistent with a tyrosinate-Fe(III) ligand-to-metal charge transfer transition. Incubation of as-isolated DddQ with added iron increases the intensity of the 550 nm peak, whereas addition of dithionite causes a bleaching as Fe(III) is reduced. Both the Fe(III) oxidized and Fe(II) reduced species are active, with similar kcat values and 2-fold differences in their Km values for DMSP. The slow turnover of Fe(III)-bound DddQ allowed us to capture a substrate-bound form of the enzyme. Our DMSP-Fe(III)-DddQ structure reveals conformational changes associated with substrate binding and shows that DMSP is positioned optimally to bind iron and is in the proximity of Tyr 120 that acts as a Lewis base to initiate catalysis. The structures of Tris-, DMSP-, and acrylate-bound forms of Fe(III)-DddQ reported here illustrate various states of the enzyme along the reaction pathway. These results provide new insights into DMSP lyase catalysis and have broader significance for understanding the mechanism of oceanic DMS production.
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Affiliation(s)
- Adam E Brummett
- Department of Chemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Mishtu Dey
- Department of Chemistry, The University of Iowa , Iowa City, Iowa 52242, United States
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15
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Enzymatic breakage of dimethylsulfoniopropionate — a signature molecule for life at sea. Curr Opin Chem Biol 2016; 31:58-65. [DOI: 10.1016/j.cbpa.2016.01.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/11/2016] [Accepted: 01/15/2016] [Indexed: 11/18/2022]
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16
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Wang P, Chen X, Li C, Gao X, Zhu D, Xie B, Qin Q, Zhang X, Su H, Zhou B, Xun L, Zhang Y. Structural and molecular basis for the novel catalytic mechanism and evolution of
DddP
, an abundant peptidase‐like bacterial Dimethylsulfoniopropionate lyase: a new enzyme from an old fold. Mol Microbiol 2015; 98:289-301. [DOI: 10.1111/mmi.13119] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Peng Wang
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Xiu‐Lan Chen
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Chun‐Yang Li
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Xiang Gao
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - De‐yu Zhu
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Bin‐Bin Xie
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Qi‐Long Qin
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Xi‐Ying Zhang
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Hai‐Nan Su
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Bai‐Cheng Zhou
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
| | - Lu‐ying Xun
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
| | - Yu‐Zhong Zhang
- State Key Laboratory of Microbial Technology Shandong University Jinan 250100 China
- Marine Biotechnology Research Center Shandong University Jinan 250100 China
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Brummett AE, Schnicker NJ, Crider A, Todd JD, Dey M. Biochemical, Kinetic, and Spectroscopic Characterization of Ruegeria pomeroyi DddW--A Mononuclear Iron-Dependent DMSP Lyase. PLoS One 2015; 10:e0127288. [PMID: 25993446 PMCID: PMC4437653 DOI: 10.1371/journal.pone.0127288] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/13/2015] [Indexed: 11/19/2022] Open
Abstract
The osmolyte dimethylsulfoniopropionate (DMSP) is a key nutrient in marine environments and its catabolism by bacteria through enzymes known as DMSP lyases generates dimethylsulfide (DMS), a gas of importance in climate regulation, the sulfur cycle, and signaling to higher organisms. Despite the environmental significance of DMSP lyases, little is known about how they function at the mechanistic level. In this study we biochemically characterize DddW, a DMSP lyase from the model roseobacter Ruegeria pomeroyi DSS-3. DddW is a 16.9 kDa enzyme that contains a C-terminal cupin domain and liberates acrylate, a proton, and DMS from the DMSP substrate. Our studies show that as-purified DddW is a metalloenzyme, like the DddQ and DddP DMSP lyases, but contains an iron cofactor. The metal cofactor is essential for DddW DMSP lyase activity since addition of the metal chelator EDTA abolishes its enzymatic activity, as do substitution mutations of key metal-binding residues in the cupin motif (His81, His83, Glu87, and His121). Measurements of metal binding affinity and catalytic activity indicate that Fe(II) is most likely the preferred catalytic metal ion with a nanomolar binding affinity. Stoichiometry studies suggest DddW requires one Fe(II) per monomer. Electronic absorption and electron paramagnetic resonance (EPR) studies show an interaction between NO and Fe(II)-DddW, with NO binding to the EPR silent Fe(II) site giving rise to an EPR active species (g = 4.29, 3.95, 2.00). The change in the rhombicity of the EPR signal is observed in the presence of DMSP, indicating that substrate binds to the iron site without displacing bound NO. This work provides insight into the mechanism of DMSP cleavage catalyzed by DddW.
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Affiliation(s)
- Adam E. Brummett
- Department of Chemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Nicholas J. Schnicker
- Department of Chemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Alexander Crider
- Department of Chemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Jonathan D. Todd
- School of Biological Sciences, University of East Anglia, Norwich Research Park, United Kingdom
| | - Mishtu Dey
- Department of Chemistry, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Dickschat JS, Rabe P, Citron CA. The chemical biology of dimethylsulfoniopropionate. Org Biomol Chem 2015; 13:1954-68. [DOI: 10.1039/c4ob02407a] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review addresses synthesis, biosynthesis, transport and degradation of dimethylsulfoniopropionate and its derivatives.
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Affiliation(s)
- Jeroen S. Dickschat
- Kekulé-Institut für Organische Chemie und Biochemie
- Rheinische Friedrich-Wilhelms-Universität Bonn
- 53121 Bonn
- Germany
- Institut für Organische Chemie
| | - Patrick Rabe
- Kekulé-Institut für Organische Chemie und Biochemie
- Rheinische Friedrich-Wilhelms-Universität Bonn
- 53121 Bonn
- Germany
- Institut für Organische Chemie
| | - Christian A. Citron
- Kekulé-Institut für Organische Chemie und Biochemie
- Rheinische Friedrich-Wilhelms-Universität Bonn
- 53121 Bonn
- Germany
- Institut für Organische Chemie
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