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Yu F, Zhang B, Liu Y, Luo W, Chen H, Gao J, Ye X, Li J, Xie Q, Peng T, Wang H, Huang T, Hu Z. Biotransformation of HBCDs by the microbial communities enriched from mangrove sediments. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:134036. [PMID: 38493623 DOI: 10.1016/j.jhazmat.2024.134036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/29/2024] [Accepted: 03/12/2024] [Indexed: 03/19/2024]
Abstract
1,2,5,6,9,10-Hexabromocyclododecanes (HBCDs) are a sort of persistent organic pollutants (POPs). This research investigated 12 microbial communities enriched from sediments of four mangroves in China to transform HBCDs. Six microbial communities gained high transformation rates (27.5-97.7%) after 12 generations of serial transfer. Bacteria were the main contributors to transform HBCDs rather than fungi. Analyses on the bacterial compositions and binning genomes showed that Alcanivorax (55.246-84.942%) harboring haloalkane dehalogenase genes dadAH and dadBH dominated the microbial communities with high transformation rates. Moreover, expressions of dadAH and dadBH in the microbial communities and Alcanivorax isolate could be induced by HBCDs. Further, it was found that purified proteins DadAH and DadBH showed high conversion rates on HBCDs in 36 h (91.9 ± 7.4 and 101.0 ± 1.8%, respectively). The engineered Escherichia coli BL21 strains harbored two genes could convert 5.7 ± 0.4 and 35.1 ± 0.1% HBCDs, respectively, lower than their cell-free crude extracts (61.2 ± 5.2 and 56.5 ± 8.7%, respectively). The diastereoisomer-specific transforming trend by both microbial communities and enzymes were γ- > α- > β-HBCD, differed from α- > β- > γ-HBCD by the Alcanivorax isolate. The identified transformation products indicated that HBCDs were dehalogenated via HBr elimination (dehydrobromination), hydrolytic and reductive debromination pathways in the enriched cultures. Two enzymes converted HBCDs via hydrolytic debromination. The present research provided theoretical bases for the biotransformation of HBCDs by microbial community and the bioremediation of HBCDs contamination in the environment.
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Affiliation(s)
- Fei Yu
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Bing Zhang
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Yongjin Liu
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Wenqi Luo
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Haonan Chen
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Jun'na Gao
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Xueying Ye
- School of Life Sciences, Huizhou University, Huizhou 516007, Guangdong Province, China
| | - Jin Li
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou 515063, Guangdong Province, China
| | - Qingyi Xie
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Tao Peng
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Hui Wang
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Tongwang Huang
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China
| | - Zhong Hu
- Department of Biology, College of Science, Shantou University, Shantou 515063, Guangdong Province, China.
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Mazur A, Grinkevich P, Chaloupkova R, Havlickova P, Kascakova B, Kuty M, Damborsky J, Kuta Smatanova I, Prudnikova T. Structural Analysis of the Ancestral Haloalkane Dehalogenase AncLinB-DmbA. Int J Mol Sci 2021; 22:ijms222111992. [PMID: 34769421 PMCID: PMC8584953 DOI: 10.3390/ijms222111992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022] Open
Abstract
Haloalkane dehalogenases (EC 3.8.1.5) play an important role in hydrolytic degradation of halogenated compounds, resulting in a halide ion, a proton, and an alcohol. They are used in biocatalysis, bioremediation, and biosensing of environmental pollutants and also for molecular tagging in cell biology. The method of ancestral sequence reconstruction leads to prediction of sequences of ancestral enzymes allowing their experimental characterization. Based on the sequences of modern haloalkane dehalogenases from the subfamily II, the most common ancestor of thoroughly characterized enzymes LinB from Sphingobium japonicum UT26 and DmbA from Mycobacterium bovis 5033/66 was in silico predicted, recombinantly produced and structurally characterized. The ancestral enzyme AncLinB-DmbA was crystallized using the sitting-drop vapor-diffusion method, yielding rod-like crystals that diffracted X-rays to 1.5 Å resolution. Structural comparison of AncLinB-DmbA with their closely related descendants LinB and DmbA revealed some differences in overall structure and tunnel architecture. Newly prepared AncLinB-DmbA has the highest active site cavity volume and the biggest entrance radius on the main tunnel in comparison to descendant enzymes. Ancestral sequence reconstruction is a powerful technique to study molecular evolution and design robust proteins for enzyme technologies.
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Affiliation(s)
- Andrii Mazur
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Pavel Grinkevich
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Radka Chaloupkova
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; (R.C.); (J.D.)
- Enantis Ltd., Kamenice 771/34, 625 00 Brno, Czech Republic
| | - Petra Havlickova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Barbora Kascakova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Michal Kuty
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; (R.C.); (J.D.)
- International Clinical Research Center, St Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Ivana Kuta Smatanova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
- Correspondence: (I.K.S.); (T.P.)
| | - Tatyana Prudnikova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
- Correspondence: (I.K.S.); (T.P.)
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Abstract
The application of native enzymes may not be economical owing to the stability factor. A smaller protein molecule may be less susceptible to external stresses. Haloalkane dehalogenases (HLDs) that act on toxic haloalkanes may be incorporated as bioreceptors to detect haloalkane contaminants. Therefore, this study aims to develop mini proteins of HLD as an alternative bioreceptor which was able to withstand extreme conditions. Initially, the mini proteins were designed through computer modeling. Based on the results, five designed mini proteins were deemed to be viable stable mini proteins. They were then validated through experimental study. The smallest mini protein (model 5) was chosen for subsequent analysis as it was expressed in soluble form. No dehalogenase activity was detected, thus the specific binding interaction of between 1,3-dibromopropane with mini protein was investigated using isothermal titration calorimetry. Higher binding affinity between 1,3-dibromopropane and mini protein was obtained than the native. Thermal stability study with circular dichroism had proven that the mini protein possessed two times higher Tm value at 83.73 °C than the native at 43.97 °C. In conclusion, a stable mini protein was successfully designed and may be used as bioreceptors in the haloalkane sensor that is suitable for industrial application.
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Vanacek P, Sebestova E, Babkova P, Bidmanova S, Daniel L, Dvorak P, Stepankova V, Chaloupkova R, Brezovsky J, Prokop Z, Damborsky J. Exploration of Enzyme Diversity by Integrating Bioinformatics with Expression Analysis and Biochemical Characterization. ACS Catal 2018. [DOI: 10.1021/acscatal.7b03523] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Pavel Vanacek
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| | - Eva Sebestova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
| | - Petra Babkova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| | - Sarka Bidmanova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| | - Lukas Daniel
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| | - Pavel Dvorak
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
| | - Veronika Stepankova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
- Enantis
Ltd., Biotechnology Incubator INBIT, Kamenice 34, 625 00 Brno, Czech Republic
| | - Radka Chaloupkova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
- Enantis
Ltd., Biotechnology Incubator INBIT, Kamenice 34, 625 00 Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
- Enantis
Ltd., Biotechnology Incubator INBIT, Kamenice 34, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- International
Clinical Research Center, St. Anne’s University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
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Chrast L, Chaloupkova R, Damborsky J. Gram-scale production of recombinant microbial enzymes in shake flasks. FEMS Microbiol Lett 2017; 365:4693837. [DOI: 10.1093/femsle/fnx265] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/02/2017] [Indexed: 11/14/2022] Open
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Bendigiri C, Zinjarde S, RaviKumar A. Ylehd, an epoxide hydrolase with promiscuous haloalkane dehalogenase activity from tropical marine yeast Yarrowia lipolytica is induced upon xenobiotic stress. Sci Rep 2017; 7:11887. [PMID: 28928379 PMCID: PMC5605520 DOI: 10.1038/s41598-017-12284-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/01/2017] [Indexed: 01/08/2023] Open
Abstract
Recalcitrant environmental pollutants, like bromoorganics and epoxides are hydrolysed with limited substrate specificities by microbial oxygenases, reductases, hydrolases and dehalogenases. Here, we report the identification and characterisation of a protein (XP_504164) from the tropical marine yeast Yarrowia lipolytica NCIM 3589, known to degrade bromoorganics and epoxides. Multiple sequence alignment suggests it belongs to α/β superfamily with conservation of catalytic triad and oxyanion hole motifs. The corresponding gene cloned and protein (Ylehd) expressed in E. coli BL21AI exhibited epoxide hydrolase activity (24 ± 0.7 nmol s−1 mg−1 protein) at pH 8.0 and promiscuous haloalkane dehalogenase (1.5 ± 0.2 nmol s−1 mg−1 protein) at pH 4.5. Recombinant Ylehd catalyses structurally diverse epoxides and bromoorganics with maximum catalytic efficiency (kcat/Km) of 96.56 and 10.1 mM−1 s−1 towards 1,2-Epoxyoctane (EO) and 1-Bromodecane (BD). The expression of Ylehd was highly induced in presence of BD and EO but not in glucose grown cells as studied by immunoblot analyses, q-PCR and activity levels. Immunoelectron microscopy confirmed higher expression in presence of xenobiotics and located it to cytosol. Such inducible nature of Ylehd suggests its physiological role in xenobiotic stress mitigation. This study represents the first functional characterisation of a bifunctional EH/HLD in eukaryotic microbes with broad substrate specificity making it a potential biocatalyst for bioremediation/biosensing of mixed pollutants.
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Affiliation(s)
- Chandrika Bendigiri
- Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India
| | - Smita Zinjarde
- Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India
| | - Ameeta RaviKumar
- Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007, India. .,Department of Biotechnology, Savitribai Phule Pune University, Pune, 411007, India.
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8
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Kotik M, Vanacek P, Kunka A, Prokop Z, Damborsky J. Metagenome-derived haloalkane dehalogenases with novel catalytic properties. Appl Microbiol Biotechnol 2017; 101:6385-6397. [PMID: 28674849 DOI: 10.1007/s00253-017-8393-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 06/11/2017] [Accepted: 06/13/2017] [Indexed: 01/30/2023]
Abstract
Haloalkane dehalogenases (HLDs) are environmentally relevant enzymes cleaving a carbon-halogen bond in a wide range of halogenated pollutants. PCR with degenerate primers and genome-walking was used for the retrieval of four HLD-encoding genes from groundwater-derived environmental DNA. Using specific primers and the environmental DNA as a template, we succeeded in generating additional amplicons, resulting altogether in three clusters of sequences with each cluster comprising 8-13 closely related putative HLD-encoding genes. A phylogenetic analysis of the translated genes revealed that three HLDs are members of the HLD-I subfamily, whereas one gene encodes an enzyme from the subfamily HLD-II. Two metagenome-derived HLDs, eHLD-B and eHLD-C, each from a different subfamily, were heterologously produced in active form, purified and characterized in terms of their thermostability, pH and temperature optimum, quaternary structure, substrate specificity towards 30 halogenated compounds, and enantioselectivity. eHLD-B and eHLD-C showed striking differences in their activities, substrate preferences, and tolerance to temperature. Profound differences were also determined in the enantiopreference and enantioselectivity of these enzymes towards selected substrates. Comparing our data with those of known HLDs revealed that eHLD-C exhibits a unique combination of high thermostability, high activity, and an unusually broad pH optimum, which covers the entire range of pH 5.5-8.9. Moreover, a so far unreported high thermostability for HLDs was determined for this enzyme at pH values lower than 6.0. Thus, eHLD-C represents an attractive and novel biocatalyst for biotechnological applications.
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Affiliation(s)
- Michael Kotik
- Laboratory of Biotransformation, Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Pavel Vanacek
- Loschmidt Laboratories, Department of Experimental Biology and Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic, Brno, Czech Republic
| | - Antonin Kunka
- Loschmidt Laboratories, Department of Experimental Biology and Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic, Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic, Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic, Brno, Czech Republic.
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9
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Discovery of Novel Haloalkane Dehalogenase Inhibitors. Appl Environ Microbiol 2016; 82:1958-1965. [PMID: 26773086 DOI: 10.1128/aem.03916-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/12/2016] [Indexed: 12/27/2022] Open
Abstract
Haloalkane dehalogenases (HLDs) have recently been discovered in a number of bacteria, including symbionts and pathogens of both plants and humans. However, the biological roles of HLDs in these organisms are unclear. The development of efficient HLD inhibitors serving as molecular probes to explore their function would represent an important step toward a better understanding of these interesting enzymes. Here we report the identification of inhibitors for this enzyme family using two different approaches. The first builds on the structures of the enzymes' known substrates and led to the discovery of less potent nonspecific HLD inhibitors. The second approach involved the virtual screening of 150,000 potential inhibitors against the crystal structure of an HLD from the human pathogen Mycobacterium tuberculosis H37Rv. The best inhibitor exhibited high specificity for the target structure, with an inhibition constant of 3 μM and a molecular architecture that clearly differs from those of all known HLD substrates. The new inhibitors will be used to study the natural functions of HLDs in bacteria, to probe their mechanisms, and to achieve their stabilization.
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Properties and biotechnological applications of natural and engineered haloalkane dehalogenases. Appl Microbiol Biotechnol 2015; 99:9865-81. [DOI: 10.1007/s00253-015-6954-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/19/2015] [Accepted: 08/22/2015] [Indexed: 01/01/2023]
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Fibinger MPC, Davids T, Böttcher D, Bornscheuer UT. A selection assay for haloalkane dehalogenase activity based on toxic substrates. Appl Microbiol Biotechnol 2015; 99:8955-62. [DOI: 10.1007/s00253-015-6686-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 05/06/2015] [Accepted: 05/08/2015] [Indexed: 12/30/2022]
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Chaloupkova R, Prudnikova T, Rezacova P, Prokop Z, Koudelakova T, Daniel L, Brezovsky J, Ikeda-Ohtsubo W, Sato Y, Kuty M, Nagata Y, Kuta Smatanova I, Damborsky J. Structural and functional analysis of a novel haloalkane dehalogenase with two halide-binding sites. ACTA ACUST UNITED AC 2014; 70:1884-97. [DOI: 10.1107/s1399004714009018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 04/21/2014] [Indexed: 11/10/2022]
Abstract
The crystal structure of the novel haloalkane dehalogenase DbeA fromBradyrhizobium elkaniiUSDA94 revealed the presence of two chloride ions buried in the protein interior. The first halide-binding site is involved in substrate binding and is present in all structurally characterized haloalkane dehalogenases. The second halide-binding site is unique to DbeA. To elucidate the role of the second halide-binding site in enzyme functionality, a two-point mutant lacking this site was constructed and characterized. These substitutions resulted in a shift in the substrate-specificity class and were accompanied by a decrease in enzyme activity, stability and the elimination of substrate inhibition. The changes in enzyme catalytic activity were attributed to deceleration of the rate-limiting hydrolytic step mediated by the lower basicity of the catalytic histidine.
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13
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Li A, Shao Z. Biochemical characterization of a haloalkane dehalogenase DadB from Alcanivorax dieselolei B-5. PLoS One 2014; 9:e89144. [PMID: 24586552 PMCID: PMC3938430 DOI: 10.1371/journal.pone.0089144] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 01/14/2014] [Indexed: 11/18/2022] Open
Abstract
Recently, we found that Alcanivorax bacteria from various marine environments were capable of degrading halogenated alkanes. Genome sequencing of A. dieselolei B-5 revealed two putative haloalkane dehalogenase (HLD) genes, which were supposed to be involved in degradation of halogenated compounds. In this report, we confirm for the first time that the Alcanivorax bacterium encodes a truly functional HLD named DadB. An activity assay with 46 halogenated substrates indicated that DadB possesses broad substrate range and has the highest overall activity among the identified HLDs. DadB prefers brominated substrates; chlorinated alkenes; and the C2-C3 substrates, including the persistent pollutants of 1,2-dichloroethane, 1,2-dichloropropane and 1,2,3-trichloropropane. As DadB displays no detectable activity toward long-chain haloalkanes such as 1-chlorohexadecane and 1-chlorooctadecane, the degradation of them in A. dieselolei B-5 might be attributed to other enzymes. Kinetic constants were determined with 6 substrates. DadB has highest affinity and largest kcat/Km value toward 1,3-dibromopropane (Km = 0.82 mM, kcat/Km = 16.43 mM−1·s−1). DadB aggregates fast in the buffers with pH≤7.0, while keeps stable in monomer form when pH≥7.5. According to homology modeling, DadB has an open active cavity with a large access tunnel, which is supposed important for larger molecules as opposed to C2-C3 substrates. Combined with the results for other HLDs, we deduce that residue I247 plays an important role in substrate selection. These results suggest that DadB and its host, A. dieselolei B-5, are of potential use for biocatalysis and bioremediation applications.
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Affiliation(s)
- Anzhang Li
- School of Life Sciences, Xiamen University, Xiamen, China ; Key Laboratory of Marine Biogenetic Resources-State Key Laboratory Breeding Base, Third Institute of Oceanography, State Oceanic Administration, Collaborative Innovation Center of Deep Sea Biology; Key Laboratory of Marine Biogenetic Resources of Fujian Province, Xiamen, China
| | - Zongze Shao
- Key Laboratory of Marine Biogenetic Resources-State Key Laboratory Breeding Base, Third Institute of Oceanography, State Oceanic Administration, Collaborative Innovation Center of Deep Sea Biology; Key Laboratory of Marine Biogenetic Resources of Fujian Province, Xiamen, China
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Skopelitou K, Georgakis N, Efrose R, Flemetakis E, Labrou NE. Sol–gel immobilization of haloalkane dehalogenase from Bradyrhizobium japonicum for the remediation 1,2-dibromoethane. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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15
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DspA from Strongylocentrotus purpuratus: The first biochemically characterized haloalkane dehalogenase of non-microbial origin. Biochimie 2013; 95:2091-6. [DOI: 10.1016/j.biochi.2013.07.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 07/30/2013] [Indexed: 01/16/2023]
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16
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Isomeric mono-, di-, and tri-bromobenzo-1H-triazoles as inhibitors of human protein kinase CK2α. PLoS One 2012; 7:e48898. [PMID: 23155426 PMCID: PMC3498355 DOI: 10.1371/journal.pone.0048898] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/03/2012] [Indexed: 02/03/2023] Open
Abstract
To further clarify the role of the individual bromine atoms of 4,5,6,7-tetrabromotriazole (TBBt), a relatively selective inhibitor of protein kinase CK2, we have examined the inhibition (IC(50)) of human CK2α by the two mono-, the four di-, and the two tri- bromobenzotriazoles relative to that of TBBt. Halogenation of the central vicinal C(5)/C(6) atoms proved to be a key factor in enhancing inhibitory activity, in that 5,6-di-Br(2)Bt and 4,5,6-Br(3)Bt were almost as effective inhibitors as TBBt, notwithstanding their marked differences in pK(a) for dissociation of the triazole proton. The decrease in pK(a) on halogenation of the peripheral C(4)/C(7) atoms virtually nullifies the gain due to hydrophobic interactions, and does not lead to a decrease in IC(50). Molecular modeling of structures of complexes of the ligands with the enzyme, as well as QSAR analysis, pointed to a balance of hydrophobic and electrostatic interactions as a discriminator of inhibitory activity. The role of halogen bonding remains debatable, as originally noted for the crystal structure of TBBt with CK2α (pdb1j91). Finally we direct attention to the promising applicability of our series of well-defined halogenated benzotriazoles to studies on inhibition of kinases other than CK2.
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Koudelakova T, Bidmanova S, Dvorak P, Pavelka A, Chaloupkova R, Prokop Z, Damborsky J. Haloalkane dehalogenases: Biotechnological applications. Biotechnol J 2012; 8:32-45. [DOI: 10.1002/biot.201100486] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 06/30/2012] [Accepted: 07/20/2012] [Indexed: 12/21/2022]
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Biochemical characterization of a novel haloalkane dehalogenase from a cold-adapted bacterium. Appl Environ Microbiol 2012; 78:4995-8. [PMID: 22582053 DOI: 10.1128/aem.00485-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A haloalkane dehalogenase, DpcA, from Psychrobacter cryohalolentis K5, representing a novel psychrophilic member of the haloalkane dehalogenase family, was identified and biochemically characterized. DpcA exhibited a unique temperature profile with exceptionally high activities at low temperatures. The psychrophilic properties of DpcA make this enzyme promising for various environmental applications.
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Sequence diversity in haloalkane dehalogenases, as revealed by PCR using family-specific primers. J Microbiol Methods 2011; 88:212-7. [PMID: 22155739 DOI: 10.1016/j.mimet.2011.11.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 11/21/2011] [Accepted: 11/21/2011] [Indexed: 11/24/2022]
Abstract
Haloalkane dehalogenases (HLDs) are hydrolytic enzymes that cleave carbon-halogen bonds in various halogenated compounds. Interest initially grew in HLDs as biocatalysts for bioremediation and later for biotransformation applications; each specific HLD within the HLD family has its own substrate specificity, enantioselectivity and product inhibition characteristics. We developed degenerate oligonucleotide primers for HLD-encoding genes and used these to PCR-amplify large hld gene fragments using genomic DNA from the microbial community of a chlorinated-solvent-contaminated aquifer as a template. An analysis of small subunit ribosomal RNA genes revealed a high complexity in the eubacterial population, dominated by α-, β- and γ-Proteobacteria, and Acidobacteria. Using HLD-family-specific primers, we also retrieved transcribed hld homologues from the microbial consortium of this contaminated site. The DNA-derived hld sequences were phylogenetically broadly distributed over both HLD subclasses I and II. Most hld sequences of the environmental RNA data set clustered in three groups within both HLD subclasses, indicating that a considerable proportion of the microbial consortium carrying hld genes was actively involved in haloalkane dehalogenation. The small sequence variation in hld genes and transcripts within each HLD cluster inferred the presence of a substantial pool of highly related HLD genes. The sequence variability appeared to be unevenly distributed over the HLD genes, however, with no apparent preference for a particular protein segment or domain.
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Abstract
An enzyme's substrate specificity is one of its most important characteristics. The quantitative comparison of broad-specificity enzymes requires the selection of a homogenous set of substrates for experimental testing, determination of substrate-specificity data and analysis using multivariate statistics. We describe a systematic analysis of the substrate specificities of nine wild-type and four engineered haloalkane dehalogenases. The enzymes were characterized experimentally using a set of 30 substrates selected using statistical experimental design from a set of nearly 200 halogenated compounds. Analysis of the activity data showed that the most universally useful substrates in the assessment of haloalkane dehalogenase activity are 1-bromobutane, 1-iodopropane, 1-iodobutane, 1,2-dibromoethane and 4-bromobutanenitrile. Functional relationships among the enzymes were explored using principal component analysis. Analysis of the untransformed specific activity data revealed that the overall activity of wild-type haloalkane dehalogenases decreases in the following order: LinB~DbjA>DhlA~DhaA~DbeA~DmbA>DatA~DmbC~DrbA. After transforming the data, we were able to classify haloalkane dehalogenases into four SSGs (substrate-specificity groups). These functional groups are clearly distinct from the evolutionary subfamilies, suggesting that phylogenetic analysis cannot be used to predict the substrate specificity of individual haloalkane dehalogenases. Structural and functional comparisons of wild-type and mutant enzymes revealed that the architecture of the active site and the main access tunnel significantly influences the substrate specificity of these enzymes, but is not its only determinant. The identification of other structural determinants of the substrate specificity remains a challenge for further research on haloalkane dehalogenases.
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Chaloupkova R, Prokop Z, Sato Y, Nagata Y, Damborsky J. Stereoselectivity and conformational stability of haloalkane dehalogenase DbjA from Bradyrhizobium japonicum USDA110: the effect of pH and temperature. FEBS J 2011; 278:2728-38. [DOI: 10.1111/j.1742-4658.2011.08203.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Hesseler M, Bogdanović X, Hidalgo A, Berenguer J, Palm GJ, Hinrichs W, Bornscheuer UT. Cloning, functional expression, biochemical characterization, and structural analysis of a haloalkane dehalogenase from Plesiocystis pacifica SIR-1. Appl Microbiol Biotechnol 2011; 91:1049-60. [DOI: 10.1007/s00253-011-3328-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Revised: 03/30/2011] [Accepted: 04/09/2011] [Indexed: 10/18/2022]
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Horisaki T, Yoshida E, Sumiya K, Takemura T, Yamane H, Nojiri H. Isolation and characterization of monochloroacetic acid-degrading bacteria. J GEN APPL MICROBIOL 2011; 57:277-84. [PMID: 22139456 DOI: 10.2323/jgam.57.277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Tadafumi Horisaki
- Biotechnology Research Center, The University of Tokyo, Tokyo, Japan
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Biochemical characteristics of the novel haloalkane dehalogenase DatA, isolated from the plant pathogen Agrobacterium tumefaciens C58. Appl Environ Microbiol 2010; 77:1881-4. [PMID: 21193677 DOI: 10.1128/aem.02109-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the biochemical characterization of a novel haloalkane dehalogenase, DatA, isolated from the plant pathogen Agrobacterium tumefaciens C58. DatA possesses a peculiar pair of halide-stabilizing residues, Asn-Tyr, which have not been reported to play this role in other known haloalkane dehalogenases. DatA has a number of other unique characteristics, including substrate-dependent and cooperative kinetics, a dimeric structure, and excellent enantioselectivity toward racemic mixtures of chiral brominated alkanes and esters.
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Prokop Z, Sato Y, Brezovsky J, Mozga T, Chaloupkova R, Koudelakova T, Jerabek P, Stepankova V, Natsume R, van Leeuwen J, Janssen D, Florian J, Nagata Y, Senda T, Damborsky J. Enantioselectivity of Haloalkane Dehalogenases and its Modulation by Surface Loop Engineering. Angew Chem Int Ed Engl 2010; 49:6111-5. [DOI: 10.1002/anie.201001753] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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26
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Prokop Z, Sato Y, Brezovsky J, Mozga T, Chaloupkova R, Koudelakova T, Jerabek P, Stepankova V, Natsume R, van Leeuwen J, Janssen D, Florian J, Nagata Y, Senda T, Damborsky J. Enantioselectivity of Haloalkane Dehalogenases and its Modulation by Surface Loop Engineering. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201001753] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Chan WY, Wong M, Guthrie J, Savchenko AV, Yakunin AF, Pai EF, Edwards EA. Sequence- and activity-based screening of microbial genomes for novel dehalogenases. Microb Biotechnol 2009; 3:107-20. [PMID: 21255311 PMCID: PMC3815952 DOI: 10.1111/j.1751-7915.2009.00155.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Dehalogenases are environmentally important enzymes that detoxify organohalogens by cleaving their carbon‐halogen bonds. Many microbial genomes harbour enzyme families containing dehalogenases, but a sequence‐based identification of genuine dehalogenases with high confidence is challenging because of the low sequence conservation among these enzymes. Furthermore, these protein families harbour a rich diversity of other enzymes including esterases and phosphatases. Reliable sequence determinants are necessary to harness genome sequencing‐efforts for accelerating the discovery of novel dehalogenases with improved or modified activities. In an attempt to extract dehalogenase sequence fingerprints, 103 uncharacterized potential dehalogenase candidates belonging to the α/β hydrolase (ABH) and haloacid dehalogenase‐like hydrolase (HAD) superfamilies were screened for dehalogenase, esterase and phosphatase activity. In this first biochemical screen, 1 haloalkane dehalogenase, 1 fluoroacetate dehalogenase and 5 l‐2‐haloacid dehalogenases were found (success rate 7%), as well as 19 esterases and 31 phosphatases. Using this functional data, we refined the sequence‐based dehalogenase selection criteria and applied them to a second functional screen, which identified novel dehalogenase activity in 13 out of only 24 proteins (54%), increasing the success rate eightfold. Four new l‐2‐haloacid dehalogenases from the HAD superfamily were found to hydrolyse fluoroacetate, an activity never previously ascribed to enzymes in this superfamily.
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Affiliation(s)
- Wing Yiu Chan
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
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Sfetsas CC, Milios L, Skopelitou K, Venieraki A, Todou R, Flemetakis E, Katinakis P, Labrou NE. Characterization of 1,2-dibromoethane-degrading haloalkane dehalogenase from Bradyrhizobium japonicum USDA110. Enzyme Microb Technol 2009. [DOI: 10.1016/j.enzmictec.2009.07.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Biochemical characterization of haloalkane dehalogenases DrbA and DmbC, Representatives of a Novel Subfamily. Appl Environ Microbiol 2009; 75:5157-60. [PMID: 19502442 DOI: 10.1128/aem.00199-09] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study focuses on two representatives of experimentally uncharacterized haloalkane dehalogenases from the subfamily HLD-III. We report biochemical characterization of the expression products of haloalkane dehalogenase genes drbA from Rhodopirellula baltica SH1 and dmbC from Mycobacterium bovis 5033/66. The DrbA and DmbC enzymes show highly oligomeric structures and very low activities with typical substrates of haloalkane dehalogenases.
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Prudnikova T, Mozga T, Rezacova P, Chaloupkova R, Sato Y, Nagata Y, Brynda J, Kuty M, Damborsky J, Smatanova IK. Crystallization and preliminary X-ray analysis of a novel haloalkane dehalogenase DbeA from Bradyrhizobium elkani USDA94. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:353-6. [PMID: 19342778 DOI: 10.1107/s1744309109007039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 02/25/2009] [Indexed: 11/10/2022]
Abstract
A novel enzyme, DbeA, belonging to the haloalkane dehalogenase family (EC 3.8.1.5) was isolated from Bradyrhizobium elkani USDA94. This haloalkane dehalogenase is closely related to the DbjA enzyme from B. japonicum USDA110 (71% sequence identity), but has different biochemical properties. DbeA is generally less active and has a higher specificity towards brominated and iodinated compounds than DbjA. In order to understand the altered activity and specificity of DbeA, its mutant variant DbeA1, which carries the unique fragment of DbjA, was also constructed. Both wild-type DbeA and DbeA1 were crystallized using the sitting-drop vapour-diffusion method. The crystals of DbeA belonged to the primitive orthorhombic space group P2(1)2(1)2(1), while the crystals of DbeA1 belonged to the monoclinic space group C2. Diffraction data were collected to 2.2 A resolution for both DbeA and DbeA1 crystals.
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Affiliation(s)
- Tatyana Prudnikova
- Institute of Physical Biology, University of South Bohemia, Nove Hrady, Czech Republic
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Mikelova R, Prokop Z, Stejskal K, Adam V, Beklova M, Trnkova L, Kulichova B, Horna A, Chaloupkova R, Damborsky J, Kizek R. Enzymatic Reaction Coupled with Flow-Injection Analysis with Charged Aerosol, Coulometric, or Amperometric Detection for Estimation of Contamination of the Environment by Pesticides. Chromatographia 2008. [DOI: 10.1365/s10337-008-0590-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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32
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Mazumdar PA, Hulecki JC, Cherney MM, Garen CR, James MN. X-ray crystal structure of Mycobacterium tuberculosis haloalkane dehalogenase Rv2579. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:351-62. [DOI: 10.1016/j.bbapap.2007.10.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 10/12/2007] [Accepted: 10/29/2007] [Indexed: 11/17/2022]
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McClay K, Schaefer CE, Vainberg S, Steffan RJ. Biodegradation of bis(2-chloroethyl) ether by Xanthobacter sp. strain ENV481. Appl Environ Microbiol 2007; 73:6870-5. [PMID: 17873075 PMCID: PMC2074973 DOI: 10.1128/aem.01379-07] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Degradation of bis(2-chloroethyl) ether (BCEE) was observed to occur in two bacterial strains. Strain ENV481, a Xanthobacter sp. strain, was isolated by enrichment culturing of samples from a Superfund site located in the northeastern United States. The strain was able to grow on BCEE or 2-chloroethylethyl ether as the sole source of carbon and energy. BCEE degradation in strain ENV481 was facilitated by sequential dehalogenation reactions resulting in the formation of 2-(2-chloroethoxy)ethanol and diethylene glycol (DEG), respectively. 2-Hydroxyethoxyacetic acid was detected as a product of DEG catabolism by the strain. Degradation of BCEE by strain ENV481 was independent of oxygen, and the strain was not able to grow on a mixture of benzene, ethylbenzene, toluene, and xylenes, other prevalent contaminants at the site. Another bacterial isolate, Pseudonocardia sp. strain ENV478 (S. Vainberg et al., Appl. Environ. Microbiol. 72:5218-5224, 2006), degraded BCEE after growth on tetrahydrofuran or propane but was not able to grow on BCEE as a sole carbon source. BCEE degradation by strain ENV478 appeared to be facilitated by a monooxygenase-mediated O-dealkylation mechanism, and it resulted in the accumulation of 2-chloroacetic acid that was not readily degraded by the strain.
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Affiliation(s)
- Kevin McClay
- Shaw Environmental, Inc., Lawrenceville, NJ 08648, USA
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Nagata Y, Endo R, Ito M, Ohtsubo Y, Tsuda M. Aerobic degradation of lindane (gamma-hexachlorocyclohexane) in bacteria and its biochemical and molecular basis. Appl Microbiol Biotechnol 2007; 76:741-52. [PMID: 17634937 DOI: 10.1007/s00253-007-1066-x] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 05/25/2007] [Accepted: 05/30/2007] [Indexed: 11/29/2022]
Abstract
gamma-Hexachlorocyclohexane (gamma-HCH, also called gamma-BHC and lindane) is a halogenated organic insecticide that causes serious environmental problems. The aerobic degradation pathway of gamma-HCH was extensively revealed in bacterial strain Sphingobium japonicum (formerly Sphingomonas paucimobilis) UT26. gamma-HCH is transformed to 2,5-dichlorohydroquinone through sequential reactions catalyzed by LinA, LinB, and LinC, and then 2,5-dichlorohydroquinone is further metabolized by LinD, LinE, LinF, LinGH, and LinJ to succinyl-CoA and acetyl-CoA, which are metabolized in the citrate/tricarboxylic acid cycle. In addition to these catalytic enzymes, a putative ABC-type transporter system encoded by linKLMN is also essential for the gamma-HCH utilization in UT26. Preliminary examination of the complete genome sequence of UT26 clearly demonstrated that lin genes for the gamma-HCH utilization are dispersed on three large circular replicons with sizes of 3.5 Mb, 682 kb, and 191 kb. Nearly identical lin genes were also found in other HCH-degrading bacterial strains, and it has been suggested that the distribution of lin genes is mainly mediated by insertion sequence IS6100 and plasmids. Recently, it was revealed that two dehalogenases, LinA and LinB, have variants with small number of amino acid differences, and they showed dramatic functional differences for the degradation of HCH isomers, indicating these enzymes are still evolving at high speed.
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Affiliation(s)
- Yuji Nagata
- Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai, 980-8577, Japan.
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Chovancová E, Kosinski J, Bujnicki JM, Damborský J. Phylogenetic analysis of haloalkane dehalogenases. Proteins 2007; 67:305-16. [PMID: 17295320 DOI: 10.1002/prot.21313] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Haloalkane dehalogenases (HLDs) are enzymes that catalyze the cleavage of carbon-halogen bonds by a hydrolytic mechanism. Although comparative biochemical analyses have been published, no classification system has been proposed for HLDs, to date, that reconciles their phylogenetic and functional relationships. In the study presented here, we have analyzed all sequences and structures of genuine HLDs and their homologs detectable by database searches. Phylogenetic analyses revealed that the HLD family can be divided into three subfamilies denoted HLD-I, HLD-II, and HLD-III, of which HLD-I and HLD-III are predicted to be sister-groups. A mismatch between the HLD protein tree and the tree of species, as well as the presence of more than one HLD gene in a few genomes, suggest that horizontal gene transfers, and perhaps also multiple gene duplications and losses have been involved in the evolution of this family. Most of the biochemically characterized HLDs are found in the HLD-II subfamily. The dehalogenating activity of two members of the newly identified HLD-III subfamily has only recently been confirmed, in a study motivated by this phylogenetic analysis. A novel type of the catalytic pentad (Asp-His-Asp+Asn-Trp) was predicted for members of the HLD-III subfamily. Calculation of the evolutionary rates and lineage-specific innovations revealed a common conserved core as well as a set of residues that characterizes each HLD subfamily. The N-terminal part of the cap domain is one of the most variable regions within the whole family as well as within individual subfamilies, and serves as a preferential site for the location of relatively long insertions. The highest variability of discrete sites was observed among residues that are structural components of the access channels. Mutations at these sites modify the anatomy of the channels, which are important for the exchange of ligands between the buried active site and the bulk solvent, thus creating a structural basis for the molecular evolution of new substrate specificities. Our analysis sheds light on the evolutionary history of HLDs and provides a structural framework for designing enzymes with new specificities.
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Affiliation(s)
- Eva Chovancová
- Loschmidt Laboratories, Faculty of Science, Masaryk University, Brno, Czech Republic
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Pavlová M, Klvana M, Jesenská A, Prokop Z, Konecná H, Sato T, Tsuda M, Nagata Y, Damborský J. The identification of catalytic pentad in the haloalkane dehalogenase DhmA from Mycobacterium avium N85: Reaction mechanism and molecular evolution. J Struct Biol 2007; 157:384-92. [PMID: 17084094 DOI: 10.1016/j.jsb.2006.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 09/08/2006] [Accepted: 09/12/2006] [Indexed: 11/20/2022]
Abstract
Haloalkane dehalogenase DhmA from Mycobacterium avium N85 showed poor expression and low stability when produced in Escherichia coli. Here, we present expression DhmA in newly constructed pK4RP rhodococcal expression system in a soluble and stable form. Site-directed mutagenesis was used for the identification of a catalytic pentad, which makes up the reaction machinery of all currently known haloalkane dehalogenases. The putative catalytic triad Asp123, His279, Asp250 and the first halide-stabilizing residue Trp124 were deduced from sequence comparisons. The second stabilizing residue Trp164 was predicted from a homology model. Five point mutants in the catalytic pentad were constructed, tested for activity and were found inactive. A two-step reaction mechanism was proposed for DhmA. Evolution of different types of catalytic pentads and molecular adaptation towards the synthetic substrate 1,2-dichloroethane within the protein family is discussed.
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Affiliation(s)
- Martina Pavlová
- Loschmidt Laboratories, Masaryk University, Brno, Czech Republic
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Affiliation(s)
- Dick B Janssen
- Biochemical Laboratory, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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