1
|
Orsini SS, James KL, Reyes DJ, Couto‐Rodriguez RL, Gulko MK, Witte A, Carroll RK, Rice KC. Bacterial-like nitric oxide synthase in the haloalkaliphilic archaeon Natronomonas pharaonis. Microbiologyopen 2020; 9:e1124. [PMID: 33306280 PMCID: PMC7658456 DOI: 10.1002/mbo3.1124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022] Open
Abstract
Bacterial nitric oxide (NO) synthases (bNOS) play diverse and important roles in microbial physiology, stress resistance, and virulence. Although bacterial and mammalian NOS enzymes have been well-characterized, comparatively little is known about the prevalence and function of NOS enzymes in Archaea. Analysis of archaeal genomes revealed that highly conserved bNOS homologs were restricted to members of the Halobacteria. Of these, Natronomonas pharaonis NOS (npNOS) was chosen for further characterization. NO production was confirmed in heterologously expressed His-tagged npNOS by coupling nitrite production from N-hydroxy-L-arginine in an H2O2-supported reaction. Additionally, the nos gene was successfully targeted and disrupted to create a Nmn. pharaonis nos mutant by adapting an established Natrialba magadii transformation protocol. Genome re-sequencing of this mutant revealed an additional frameshift in a putative cation-acetate symporter gene, which could contribute to altered acetate metabolism in the nos mutant. Inactivation of Nmn. pharaonis nos was also associated with several phenotypes congruent with bacterial nos mutants (altered growth, increased oxygen consumption, increased pigment, increased UV susceptibility), suggesting that NOS function may be conserved between bacteria and archaea. These studies are the first to describe genetic inactivation and characterization of a Nmn. pharaonis gene and provides enhanced tools for probing its physiology.
Collapse
Affiliation(s)
- Silvia S. Orsini
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
- Present address:
Pharma ServicesViral Vector ServicesThermo Fisher ScientificAlachuaFLUSA
| | - Kimberly L. James
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
| | - Destiny J. Reyes
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
- Present address:
Pharma ServicesViral Vector ServicesThermo Fisher ScientificAlachuaFLUSA
| | | | - Miriam K. Gulko
- Department OesterheltMax Planck Institut für BiochemieMartinsriedGermany
| | - Angela Witte
- Department of Microbiology, Immunobiology and GeneticsMPL LaboratoriesUniversity of ViennaViennaAustria
| | | | - Kelly C. Rice
- Department of Microbiology and Cell ScienceIFASUniversity of FloridaGainesvilleFLUSA
| |
Collapse
|
2
|
Abstract
This study presents the first example of an alcohol dehydrogenase (ADH) from the halophilic archaeum Haloquadratum walsbyi (HwADH). A hexahistidine-tagged recombinant HwADH was heterologously overexpressed in Haloferax volcanii. HwADH was purified in one step and was found to be thermophilic with optimal activity at 65 °C. HwADH was active in the presence of 10% (v/v) organic solvent. The enzyme displayed dual cofactor specificity and a broad substrate scope, and maximum activity was detected with benzyl alcohol and 2-phenyl-1-propanol. HwADH accepted aromatic ketones, acetophenone and phenylacetone as substrates. The enzyme also accepted cyclohexanol and aromatic secondary alcohols, 1-phenylethanol and 4-phenyl-2-butanol. H. walsbyi may offer an excellent alternative to other archaeal sources to expand the toolbox of halophilic biocatalysts.
Collapse
Affiliation(s)
- Jennifer Cassidy
- School of Chemistry, University of Nottingham, University Park, NG7 2RD, UK
- Synthesis and Solid State Pharmaceutical Centre (SSPC), School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Francesca Paradisi
- School of Chemistry, University of Nottingham, University Park, NG7 2RD, UK.
- Synthesis and Solid State Pharmaceutical Centre (SSPC), School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland.
| |
Collapse
|
3
|
Menasria T, Aguilera M, Hocine H, Benammar L, Ayachi A, Si Bachir A, Dekak A, Monteoliva-Sánchez M. Diversity and bioprospecting of extremely halophilic archaea isolated from Algerian arid and semi-arid wetland ecosystems for halophilic-active hydrolytic enzymes. Microbiol Res 2018; 207:289-298. [PMID: 29458865 DOI: 10.1016/j.micres.2017.12.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/15/2017] [Accepted: 12/23/2017] [Indexed: 11/19/2022]
Abstract
The diversity of haloarchaea associated with different dry salt lakes in northeastern Algeria was investigated together with their potential of hydrolytic enzyme production. A total of 68 aerobic halophilic archaea were isolated from saline sediments. Based on the 16S rRNA gene sequencing, the isolates were assigned to seven phylotypes within the class Halobacteria, namely Haloarcula, Halococcus, Haloferax, Halogeometricum, Haloterrigena, Natrialba, and Natrinema. The results showed that Haloferax group was found to be dominant in all samples (30 isolates) (44%) with high diversity, followed by Halococcus spp. (13%) (9 isolates). All phylotypes are extreme halophiles and thermotolerant with the ability to grow at temperatures up to 48 °C. In addition, the screening for extracellular halophilic enzymes showed that 89.7% of the isolates were able to produce at least two types of the screened enzymes. The strains producing esterase, gelatinase, inulinase, cellulase and protease activities were the most diverse functional group. These data showed an abundant and diverse haloarchaeal community, detected in Algerian wetland ecosystems, presenting a promising source of molecules with important biotechnological applications.
Collapse
Affiliation(s)
- Taha Menasria
- Department of Microbiology and Biochemistry, Faculty of Natural and Life Sciences University of Batna 2, Batna 05078, Algeria; Department of Microbiology, School of Pharmacy, University of Granada, Granada, Spain; Department of Applied Biology, Faculty of Exact Sciences and Natural and Life Sciences, University of Tebessa, Tebessa 12002, Algeria.
| | - Margarita Aguilera
- Department of Microbiology, School of Pharmacy, University of Granada, Granada, Spain.
| | - Hacene Hocine
- Cellular and Molecular Biology Laboratory, University of Sciences and Technology Houari Boumediene, Bp 32, El Alia, 16111 Bab Ezzouar, Algiers, Algeria
| | - Leyla Benammar
- Department of Microbiology and Biochemistry, Faculty of Natural and Life Sciences University of Batna 2, Batna 05078, Algeria
| | - Ammar Ayachi
- Veterinary and Agricultural Sciences Institute, Department of Veterinary Sciences, University of Batna 1, Batna 05000, Algeria
| | - Abdelkrim Si Bachir
- Department of Ecology and Environment, Faculty of Natural and Life Sciences, University of Batna 2, Batna 05078, Algeria
| | - Ahmed Dekak
- Department of Applied Biology, Faculty of Exact Sciences and Natural and Life Sciences, University of Tebessa, Tebessa 12002, Algeria
| | | |
Collapse
|
4
|
Torregrosa-Crespo J, González-Torres P, Bautista V, Esclapez JM, Pire C, Camacho M, Bonete MJ, Richardson DJ, Watmough NJ, Martínez-Espinosa RM. Analysis of multiple haloarchaeal genomes suggests that the quinone-dependent respiratory nitric oxide reductase is an important source of nitrous oxide in hypersaline environments. Environ Microbiol Rep 2017; 9:788-796. [PMID: 28925557 DOI: 10.1111/1758-2229.12596] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Microorganisms, including Bacteria and Archaea, play a key role in denitrification, which is the major mechanism by which fixed nitrogen returns to the atmosphere from soil and water. While the enzymology of denitrification is well understood in Bacteria, the details of the last two reactions in this pathway, which catalyse the reduction of nitric oxide (NO) via nitrous oxide (N2 O) to nitrogen (N2 ), are little studied in Archaea, and hardly at all in haloarchaea. This work describes an extensive interspecies analysis of both complete and draft haloarchaeal genomes aimed at identifying the genes that encode respiratory nitric oxide reductases (Nors). The study revealed that the only nor gene found in haloarchaea is one that encodes a single subunit quinone dependent Nor homologous to the qNor found in bacteria. This surprising discovery is considered in terms of our emerging understanding of haloarchaeal bioenergetics and NO management.
Collapse
Affiliation(s)
- Javier Torregrosa-Crespo
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| | - Pedro González-Torres
- Bioinformatics and Genomics Program, Centre for Genomic Regulation (CRG), Dr. Aiguader, 88. 08003 Barcelona, Spain
| | - Vanesa Bautista
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| | - Julia M Esclapez
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| | - Carmen Pire
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| | - Mónica Camacho
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| | - María José Bonete
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| | - David J Richardson
- Centre for Molecular Structure and Biochemistry, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Nicholas J Watmough
- Centre for Molecular Structure and Biochemistry, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Rosa María Martínez-Espinosa
- Department of Agrochemistry and Biochemistry. Faculty of Science, University of Alicante, Ap. 99, E-03080 Alicante, Spain
| |
Collapse
|
5
|
Yang DD, Li Q, Huang JJ, Chen M. [Diversity and enzyme-producing activity of culturable halophilic bacteria in Daishan Saltern of East China]. Ying Yong Sheng Tai Xue Bao 2012; 23:3103-3108. [PMID: 23431797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Soil and saline water samples were collected from the Daishan Saltern of East China, and the halophilic bacteria were isolated and cultured by using selective media, aimed to investigate the diversity and enzyme-producing activity of culturable halophilic bacteria in saltern environment. A total of 181 strains were isolated by culture-dependent method. Specific primers were used to amplify the 16S rRNA gene of bacteria and archaea. The operation taxonomy units (OTUs) were determined by ARDRA method, and the representative strain of each OTU was sequenced. The phylogenetic position of all the isolated strains was determined by 16S rRNA sequencing. The results showed that the isolated 181 strains displayed 21 operational taxonomic units (OTUs), of which, 12 OTUs belonged to halophilic bacteria, and the others belonged to halophilic archaea. Phylogenetic analysis indicated that there were 7 genera presented among the halophilic bacteria group, and 4 genera presented among the halophilic archaea group. The dominant halophilic strains were of Halomonas and Haloarcula, with 46.8% in halophilic bacteria and 49.1% in halophilic archaea group, respectively. Enzyme-producing analysis indicated that most strains displayed enzyme-producing activity, including the activities of producing amylase, proteinase and lipase, and the dominant strains capable of enzyme-producing were of Haloarcula. Our results showed that in the environment of Daishan Saltern, there existed a higher diversity of halophilic bacteria, being a source sink for screening enzyme-producing bacterial strains.
Collapse
Affiliation(s)
- Dan-Dan Yang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
| | | | | | | |
Collapse
|
6
|
Sastre DE, Paggi RA, De Castro RE. The Lon protease from the haloalkaliphilic archaeon Natrialba magadii is transcriptionally linked to a cluster of putative membrane proteases and displays DNA-binding activity. Microbiol Res 2010; 166:304-13. [PMID: 20869220 DOI: 10.1016/j.micres.2010.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 07/08/2010] [Accepted: 07/10/2010] [Indexed: 01/22/2023]
Abstract
The ATP-dependent Lon protease is universally distributed in bacteria, eukaryotic organelles and archaea. In comparison with bacterial and eukaryal Lon proteases, the biology of the archaeal Lon has been studied to a limited extent. In this study, the gene encoding the Lon protease of the alkaliphilic haloarchaeon Natrialba magadii (Nmlon) was cloned and sequenced, and the genetic organization of Nmlon was examined at the transcriptional level. Nmlon encodes a 84 kDa polypeptide with a pI of 4.42 which contains the ATPase, protease and membrane targeting domains of the archaeal-type LonB proteases. Nmlon is part of an operon that encodes membrane proteases and it is transcribed as a polycistronic mRNA in N. magadii cells at different growth stages. Accordingly, NmLon was detected in cell membranes of N. magadii throughout growth by Western blot analysis using specific anti-NmLon antibodies. Interestingly, in electrophoretic mobility shift assays, purified NmLon bound double stranded as well as single stranded DNA in the presence of elevated salt concentrations. This finding shows that DNA-binding is conserved in the LonA and LonB subfamilies and suggests that Lon-DNA interaction may be relevant for its function in haloarchaea.
Collapse
Affiliation(s)
- Diego E Sastre
- Instituto de Investigaciones Biológicas, UNMDP-CONICET, Funes 3250 4 to Nivel, Mar del Plata 7600, Argentina
| | | | | |
Collapse
|
7
|
D'Alessandro CP, De Castro RE, Giménez MI, Paggi RA. Effect of nutritional conditions on extracellular protease production by the haloalkaliphilic archaeon Natrialba magadii. Lett Appl Microbiol 2007; 44:637-42. [PMID: 17576226 DOI: 10.1111/j.1472-765x.2007.02122.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The effect of various nitrogen sources and nutritional starvation was examined on the production of an extracellular protease secreted by the haloalkaliphilic archaeon Natrialba magadii. METHODS AND RESULTS Cell growth and proteolytic activity were measured in cells grown with different nitrogen sources. Proteolytic activity was produced in complex and easily metabolized nitrogen sources such as yeast extract, casein and casamino acids; meanwhile, ammonium repressed enzyme production. The time course and amount of protease accumulated showed an inverse correlation with growth rate and nutrient concentration. Starvation did not induce extracellular protease production. CONCLUSION The accumulation of Nab. magadii extracellular protease is stimulated by nutrient limitation and slow growth rate indicating that it is probably induced in response to a deficit in the energetic status of the cells. Nutritional starvation did not induce protease accumulation suggesting that de novo synthesis of this protease and/or factor/s necessary for its activation are required. This enzyme may be regulated by nitrogen catabolite repression and it does not require protein substrates for induction. SIGNIFICANCE AND IMPACT OF THE STUDY These results contribute to the basic knowledge on protease regulation in haloalkaliphilic archaea and will help to optimize the production of this extremozyme for biotechnological applications such as protease-catalysed peptide synthesis.
Collapse
Affiliation(s)
- C P D'Alessandro
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | | | | | | |
Collapse
|
8
|
Shi WL, Zhong CQ, Tang B, Shen P. [Purification and characterization of extracellular halophilic protease from haloarchaea Natrinema sp. R6-5]. Wei Sheng Wu Xue Bao 2007; 47:161-3. [PMID: 17436645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A halophilic extracellular protease from a halophilic archaea Natrinema sp. R6-5 was purified to SDS-PAGE homogeneity using bacitracin-Sepharose 4B chromatography. A molecular mass of the purified protease subunit was 62KD determined by SDS-PAGE. The protease activity was inhibited by phenylmethylsulfonyl fluoride (PMSF), suggesting that the protease belong to serine protease. The protease exhibited optimum NaCl concentration is 3 mol/L. At the 3 mol/L NaCl concentration, the optimum temperature and the optimum pH were 45 degrees C and 8.0. The protease could keep high activity and stability in high salt environment and had potential application value.
Collapse
Affiliation(s)
- Wan-liang Shi
- College of Life Science, Wuhan University, Wuhan 430072, China.
| | | | | | | |
Collapse
|
9
|
Vidyasagar M, Prakash SB, Sreeramulu K. Optimization of culture conditions for the production of haloalkaliphilic thermostable protease from an extremely halophilic archaeon Halogeometricum sp. TSS101. Lett Appl Microbiol 2006; 43:385-91. [PMID: 16965368 DOI: 10.1111/j.1472-765x.2006.01980.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS Isolation and screening of extreme halophilic archaeon producing extracellular haloalkaliphilic protease and optimization of culture conditions for its maximum production. METHODS AND RESULTS Halogeometricum sp. TSS101 was isolated from salt samples and screened for the secretion of protease on gelatin and casein plates containing 20% NaCl. The archaeon was grown aerobically in a 250 ml flask containing 50 ml of (w/v) NaCl 20%; MgCl(2) 1%; KCl 0.5%; trisodium citrate 0.3%; and peptone 1%; pH 7.2 at 40 degrees C on rotary shaker. The production of enzyme was investigated at various pH, temperatures, NaCl concentrations, metal ions and different carbon and nitrogen sources. The partially purified protease had activity in a broad pH range (7.0-10.0) with optimum activity at pH 10.0 and a temperature (60 degrees C). The enzyme was thermostable and retained 70% initial activity at 80 degrees C. Maximum protease production occurred at 40 degrees C in a medium containing 20% NaCl (w/v) and 1% skim milk powder after 84 h in shaking culture. Enzyme secretion was observed at a broad pH range of 7.0-10.0. Addition of CaCl(2) (200 mmol) to the culture medium enhanced the production of protease. Protein rich flours proved to be cheap and good alternative source for enzyme production. Different osmolytes were tested for the growth and production of haloalkaliphilc protease and found that betaine and glycerol enhanced growth without secretion of the protease. Immobilization studies showed that whole cells immobilized in 2% alginate beads were stable up to 10 batches and able to secrete the protease, which attained maximum production within 60 h under shaking conditions. CONCLUSIONS Halogeometricum sp. TSS101 secreted an extracellular haloalkaliphilic and thermostable protease. The optimum conditions required for maximum production are 20% NaCl, 1% skim milk powder and temperature at 40 degrees C. Addition of CaCl(2) (200 mmol) enhanced the enzyme production. Immobilization of whole cells in absence of NaCl proved to be useful for continuous production of haloalkaliphilic protease. SIGNIFICANCE AND IMPACT OF THE STUDY The low cost protein rich flours were used as an alternative carbon and nitrogen sources for enzyme production. Immobilization of halophilic cells in alginate beads can be used in continuous production of halophilic enzyme. The halophilic and thermostable protease from Halogeometricum sp. TSS101 is good source for industrial applications and can be a suitable source for preparation of fish sauce.
Collapse
Affiliation(s)
- M Vidyasagar
- Department of Biochemistry, Gulbarga University, Gulbarga, 585106, India
| | | | | |
Collapse
|
10
|
Ruiz DM, De Castro RE. Effect of organic solvents on the activity and stability of an extracellular protease secreted by the haloalkaliphilic archaeon Natrialba magadii. J Ind Microbiol Biotechnol 2006; 34:111-5. [PMID: 17024426 DOI: 10.1007/s10295-006-0174-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Accepted: 08/25/2006] [Indexed: 10/24/2022]
Abstract
The effect of various organic solvents on the activity and stability of an extracellular protease produced by the haloalkaliphilic archaeon Natrialba magadii was tested. This protease was active and stable in aqueous-organic solvent mixtures containing 1.5 M NaCl and glycerol, dimethylsulfoxide (DMSO), N,N-dimethyl formamide, propylenglycol, and dioxane. Among the solvents tested, DMSO, propylenglycol, and glycerol were effective in preserving enzyme stability in suboptimal NaCl concentrations. The stabilizing effect of DMSO on this haloalkaliphilic protease was more efficient at pH 8 than at pH 10, suggesting that DMSO may not substitute for salt to allow halophilic proteins to withstand the effect of high pH values. These results show that Nab. magadii extracellular protease is a solvent tolerant enzyme and suggest a potential application of this haloalkaliphilic protease in aqueous-organic solvent biocatalysis.
Collapse
Affiliation(s)
- Diego M Ruiz
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1245, Mar del Plata, 7600, Argentina
| | | |
Collapse
|
11
|
Vidyasagar M, Prakash S, Litchfield C, Sreeramulu K. Purification and characterization of a thermostable, haloalkaliphilic extracellular serine protease from the extreme halophilic archaeon Halogeometricum borinquense strain TSS101. Archaea 2006; 2:51-7. [PMID: 16877321 PMCID: PMC2685586 DOI: 10.1155/2006/430763] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A novel haloalkaliphilic, thermostable serine protease was purified from the extreme halophilic archaeon, Halogeometricum borinquense strain TSS101. The protease was isolated from a stationary phase culture, purified 116-fold with 18% yield and characterized biochemically. The molecular mass of the purified enzyme was estimated to be 86 kDa. The enzyme showed the highest activity at 60 degrees C and pH 10.0 in 20% NaCl. The enzyme had high activity over the pH range from 6.0 to 10.0. Enzymatic activity was strongly inhibited by 1 mM phenyl methylsulfonyl fluoride, but activity was increased 59% by 0.1% cetyltrimethylammonium bromide. The enzyme exhibited relatively high thermal stability, retaining 80% of its activity after 1 h at 90 degrees C. Thermostability increased in the presence of Ca2+. The stability of the enzyme was maintained in 10% sucrose and in the absence of NaCl.
Collapse
Affiliation(s)
| | - S. Prakash
- Department of Biochemistry, Gulbarga University, Gulbarga-585 106, Karnataka, India
| | - Carol Litchfield
- Department of Environmental Science and Policy, George Mason University, 10900 University Blvd., PW1 MS 4D4, Manassas, Virginia, 20110
| | - K. Sreeramulu
- Department of Biochemistry, Gulbarga University, Gulbarga-585 106, Karnataka, India
- Corresponding author ()
| |
Collapse
|
12
|
Abstract
Proteases play key roles in many biological processes and have numerous applications in biotechnology and industry. Recent advances in the genetics, genomics and biochemistry of the halophilic Archaea provide a tremendous opportunity for understanding proteases and their function in the context of an archaeal cell. This review summarizes our current knowledge of haloarchaeal proteases and provides a reference for future research.
Collapse
Affiliation(s)
- Rosana E De Castro
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
| | | | | | | | | |
Collapse
|
13
|
Tokunaga H, Ishibashi M, Arakawa T, Tokunaga M. Highly efficient renaturation of beta-lactamase isolated from moderately halophilic bacteria. FEBS Lett 2004; 558:7-12. [PMID: 14759507 DOI: 10.1016/s0014-5793(03)01508-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2003] [Revised: 12/08/2003] [Accepted: 12/10/2003] [Indexed: 11/29/2022]
Abstract
Most, if not all, beta-lactamases reported to date are irreversibly denatured at 60-70 degrees C. Here, we found that a halophilic beta-lactamase from the moderately halophilic bacterium Chromohalobacter sp. 560 was highly stable against heat inactivation: it retained approximately 75% of its activity after boiling for 5 min in the presence of 0.2 M NaCl, suggesting that the protein either incompletely denatures during the boiling process or readily renatures upon cooling to the assay temperature. Circular dichroism showed a complete unfolding at 60 degrees C and a full reversibility, indicating that the observed activity after boiling is due to efficient refolding following heat denaturation. The enzyme showed optimal activity at 50-60 degrees C, indicating that an increase in activity with temperature offsets the thermal denaturation. The gene bla was cloned, and the primary structure of the enzyme was deduced to be highly abundant in acidic amino acid residues, one of the characteristics of halophilic proteins. Despite its halophilic nature, the enzyme refolds in low salt media after heat denaturation.
Collapse
Affiliation(s)
- Hiroko Tokunaga
- Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
| | | | | | | |
Collapse
|
14
|
La Cara F, Alves L, Gírio F, Di Salle A, Capasso A, Rossi M. A New Dehydrogenase Specific Towards Aromatic Aldehydes From A Halophilic Bacterium. Protein Pept Lett 2003; 10:449-57. [PMID: 14561133 DOI: 10.2174/0929866033478645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new enzyme showing a dehydrogenase activity towards aromatic aldehydes was isolated, purified and characterized from a halophilic strain isolated from saline environment. The enzyme is a monomer of 54 kDa; it is rather thermostable (optimal temperature: 50 degrees C) showing a broad spectrum of activity in a large pH range with the maximum at pH 9.5. The substrate specificity and the effect of ions were evaluated and compared with analogous described proteins.
Collapse
Affiliation(s)
- F La Cara
- Institute of Protein Biochemistry-C.N.R., Via P. Castellino, 111, 80131, Naples, Italy
| | | | | | | | | | | |
Collapse
|
15
|
Abstract
Proteolytic activity and a subtilisin inhibitor (NSI) were detected in Natrialba magadii cells. The proteolytic activity was due to two different proteases: a approximately 90-kDa metallo protease (NMP) produced during exponential growth and a 246-kDa serine protease (NSP) detected in the stationary phase. Both proteases were detected in the cytosolic fraction. NSI activity was maximal during early stages of growth and decreased in the stationary phase. NSI is a 35-kDa thermosensitive protein; it inhibits NSP activity but has no effect on NMP, and it was detected as a soluble or membrane-bound protein depending on the growth phase. Our results suggest that NSI may regulate NSP activity in vivo and that this protease may have a role in stationary phase cells. To our knowledge, this is the first report on the occurrence of protease inhibitors in Archaea.
Collapse
Affiliation(s)
- María I Giménez
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Casilla de Correo 1245, (7600) Mar del Plata, Argentina
| | | | | |
Collapse
|
16
|
Wainø M, Ingvorsen K. Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis. Extremophiles 2003; 7:87-93. [PMID: 12664260 DOI: 10.1007/s00792-002-0299-y] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2002] [Accepted: 09/13/2002] [Indexed: 11/28/2022]
Abstract
The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta-xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic; beta-xylanase activity exhibiting two optima at 55 degrees and 70 degrees C, while beta-xylosidase activity was optimal at 65 degrees C. SDS-PAGE and zymogram techniques revealed the presence of two xylan-degrading proteins of approximately 45 and 67 kDa in culture supernatants. To our knowledge, this paper is the first report on hemicellulose-degrading enzymes produced by an extremely halophilic archaeon.
Collapse
Affiliation(s)
- Michael Wainø
- Danish Veterinary Institute, Hangøvej 2, 8200 Arhus N, Denmark
| | | |
Collapse
|
17
|
Abstract
AIMS The aim of this study was to determine the diversity of moderately halophilic bacteria with hydrolase activities. METHODS AND RESULTS Screening bacteria from different hypersaline environments in South Spain led to the isolation of a total of 122 moderately halophilic bacteria able to produce different hydrolases (amylases, DNases, lipases, proteases and pullulanases). These bacteria are able to grow optimally in media with 5-15% salts and in most cases up to 20-25% salts. In contrast to strains belonging to previously described species, that showed very little hydrolase activities, environmental isolates produced a great variety of hydrolases. These strains were identified as members of the genera: Salinivibrio (55 strains), Halomonas (25 strains), Chromohalobacter (two strains), Bacillus-Salibacillus (29 strains), Salinicoccus (two strains) and Marinococcus (one strain), as well as eight non-identified isolates. CONCLUSIONS Moderately halophilic bacteria are a source of hydrolytic enzymes such as amylases, DNases, lipases, proteases and pullulanases. SIGNIFICANCE AND IMPACT OF THE STUDY Although most culture collection strains are not able to produce hydrolases, it has been shown that environmental isolates can produce these potentially biotechnological important enzymes.
Collapse
Affiliation(s)
- C Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, Spain
| | | | | | | |
Collapse
|
18
|
Hezayen FF, Steinbüchel A, Rehm BHA. Biochemical and enzymological properties of the polyhydroxybutyrate synthase from the extremely halophilic archaeon strain 56. Arch Biochem Biophys 2002; 403:284-91. [PMID: 12139978 DOI: 10.1016/s0003-9861(02)00234-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Some members of the archaebacterial family Halobacteriaceae have been determined to accumulate polyhydroxyalkanoate (PHA) and poly(3-hydroxybutyrate) (PHB). The extremely halophilic archaebacterium strain 56 is capable of accumulating large amounts of PHB. Since measurements of enzyme activities related to archaebacterial PHB biosynthesis have never been achieved, we investigated the enzymology of PHB biosynthesis in strain 56. Crude extracts of strain 56 cultivated under accumulating conditions showed PHB synthase activity, whereas neither beta-ketothiolase nor NADH/NADPH-dependent acetoacetyl-CoA reductase activity was detectable. An 80-kDa protein, cross-reacting with the anti-PHB synthase antibodies raised against the PHB synthase from Ralstonia eutropha, was identified in the crude extract and was strongly enriched by purification of PHB granules. The granule-associated PHB synthase was enzymologically characterized. Enzyme kinetics showed a specific activity of about 4.6U/mg and Hill plot analysis revealed a K(0.5) of 56 microM with (R)-3-hydroxybutyryl-CoA employed as substrate. A Hill coefficient of 1.75 indicated that the PHB synthase exhibited positive cooperativity. The thioesters 3-hydroxyvaleryl-CoA, 4-hydroxybutyryl-CoA, and 3-hydroxydecanoyl-CoA were not accepted as substrates. Moreover, the PHB synthase was found to be competitively inhibited by CoA, showing an IC(50) of 160 microM. The PHB synthase was stable up to 60 degrees C and still exhibited about 90% of the maximum enzyme activity, which was obtained at 40 degrees C. In contrast to the soluble PHB synthase, the granule-bound PHB synthase was almost independent of the salt concentration. The PHB synthase could not be released from the PHB granules, indicating a covalent attachment to the PHB core. This is the first description of an archaebacterial PHA synthase.
Collapse
Affiliation(s)
- Francis F Hezayen
- Institut für Mikrobiologie der Westfälischen, Wilhelms-Universität Münster, Corrensstr. 3, D-48149, Münster, Germany
| | | | | |
Collapse
|
19
|
Polosina YY, Zamyatkin DF, Kostyukova AS, Filimonov VV, Fedorov OV. Stability of Natrialba magadii NDP kinase: comparisons with other halophilic proteins. Extremophiles 2002; 6:135-42. [PMID: 12013434 DOI: 10.1007/s007920100232] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Nucleoside diphosphate kinase from the haloalkaliphilic archaeon Natrialba magadii (Nm NDPK) is a homooligomeric hexamer with a monomer molecular weight of 23 kDa. Its main function is to exchange gamma-phosphates between nucleoside triphosphates and diphosphates. Previously it was shown that Nm NDPK is active over a wide range of NaCl concentrations, which is not typical of extremely halophilic proteins. In this paper more detailed investigations of kinase function and stability were carried out using circular dichroism, differential scanning calorimetry, size-exclusion chromatography, and biochemical methods. A possible mechanism for stabilization of halophilic proteins that allows them to function in a wide range of NaCl concentrations is proposed.
Collapse
|
20
|
Abstract
A serine protease secreted by the haloalkaliphilic archaeon Natrialba magadii at the end of the exponential growth phase was isolated. This enzyme was purified 83 fold with a total yield of 25% by ethanol precipitation, affinity chromatography, and gel filtration. The native molecular mass of the enzyme determined by gel filtration was 45 kDa. Na. magadii extracellular protease was dependent on high salt concentrations for activity and stability, and it had an optimum temperature of 60 degrees C in the presence of 1.5M NaCl. The enzyme was stable and had a broad pH profile (6-12) with an optimum pH of 8-10 for azocasein hydrolysis. The protease was strongly inhibited by diisopropyl fluorophosphate (DFP), phenylmethyl sulfonylfluoride (PMSF), and chymostatin, indicating that it is a serine protease. It was sensitive to denaturing agents such as SDS, urea, and guanidine HCl and activated by thiol-containing reducing agents such as dithiotreitol (DTT) and 2-mercaptoethanol. This protease degraded casein and gelatin and showed substrate specificity for synthetic peptides containing Phe, Tyr, and Leu at the carboxyl terminus, showing that it has chymotrypsin-like activity. Na. magadii protease presented no cross-reactivity with polyclonal antibodies raised against the extracellular protease of Natronococcus occultus, suggesting that although these proteases share several biochemical traits, they might be antigenically unrelated.
Collapse
Affiliation(s)
- M I Giménez
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Argentina
| | | | | | | |
Collapse
|
21
|
Abstract
It is now clear that the understanding of halophilic adaptation at a molecular level requires a strategy of complementary experiments, combining molecular biology, biochemistry, and cellular approaches with physical chemistry and thermodynamics. In this review, after a discussion of the definition and composition of halophilic enzymes, the effects of salt on their activity, solubility, and stability are reviewed. We then describe how thermodynamic observations, such as parameters pertaining to solvent-protein interactions or enzyme-unfolding kinetics, depend strongly on solvent composition and reveal the important role played by water and ion binding to halophilic proteins. The three high-resolution crystal structures now available for halophilic proteins are analyzed in terms of haloadaptation, and finally cellular response to salt stress is discussed briefly.
Collapse
Affiliation(s)
- D Madern
- Institut de Biologie Structurale CEA-CNRS, Grenoble, France
| | | | | |
Collapse
|
22
|
Watanabe M, Matsuo M, Tanaka S, Akimoto H, Asahi S, Nishimura S, Katze JR, Hashizume T, Crain PF, McCloskey JA, Okada N. Biosynthesis of archaeosine, a novel derivative of 7-deazaguanosine specific to archaeal tRNA, proceeds via a pathway involving base replacement on the tRNA polynucleotide chain. J Biol Chem 1997; 272:20146-51. [PMID: 9242689 DOI: 10.1074/jbc.272.32.20146] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Archaeosine is a novel derivative of 7-deazaguanosine found in transfer RNAs of most organisms exclusively in the archaeal phylogenetic lineage and is present in the D-loop at position 15. We show that this modification is formed by a posttranscriptional base replacement reaction, catalyzed by a new tRNA-guanine transglycosylase (TGT), which has been isolated from Haloferax volcanii and purified nearly to homogeneity. The molecular weight of the enzyme was estimated to be 78 kDa by SDS-gel electrophoresis. The enzyme can insert free 7-cyano-7-deazaguanine (preQ0 base) in vitro at position 15 of an H. volcanii tRNA T7 transcript, replacing the guanine originally located at that position without breakage of the phosphodiester backbone. Since archaeosine base and 7-aminomethyl-7-deazaguanine (preQ1 base) were not incorporated into tRNA by this enzyme, preQ0 base appears to be the actual substrate for the TGT of H. volcanii, a conclusion supported by characterization of preQ0 base in an acid-soluble extract of H. volcanii cells. Thus, this novel TGT in H. volcanii is a key enzyme for the biosynthetic pathway leading to archaeosine in archaeal tRNAs.
Collapse
Affiliation(s)
- M Watanabe
- Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Schmid-Appert M, Zoller K, Traber H, Vuilleumier S, Leisinger T. Association of newly discovered IS elements with the dichloromethane utilization genes of methylotrophic bacteria. Microbiology (Reading) 1997; 143 ( Pt 8):2557-2567. [PMID: 9274009 DOI: 10.1099/00221287-143-8-2557] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Dichloromethane (DCM) dehalogenases enable facultative methylotrophic bacteria to utilize DCM as sole carbon and energy source. DCM-degrading aerobic methylotrophic bacteria expressing a type A DCM dehalogenase were previously shown to share a conserved 4.2 kb BamHI DNA fragment containing the dehalogenase structural gene, dcmA, and dcmR, the gene encoding a putative regulatory protein. Sequence analysis of a 10 kb DNA fragment including this region led to the identification of three types of insertion sequences identified as IS1354, IS1355 and IS1357, and also two ORFs, orf353 and orf192, of unknown function. Two identical copies of element IS1354 flank the conserved 4.2 kb fragment as a direct repeat. The occurrence of these newly identified IS elements was shown to be limited to DCM-utilizing methylotrophs containing a type A DCM dehalogenase. The organization of the corresponding dcm regions in 12 DCM-utilizing strains was examined by hybridization analysis using IS-specific probes. Six different groups could be defined on the basis of the occurrence, position and copy number of IS sequences. All groups shared a conserved 5.6 kb core region with dcmA, dcmR, orf353 and orf192 as well as IS1357. One group of strains including Pseudomonas sp. DM1 contained two copies of this conserved core region. The high degree of sequence conservation observed within the genomic region responsible for DCM utilization and the occurrence of clusters of insertion sequences in the vicinity of the dcm genes suggest that a transposon is involved in the horizontal transfer of the DCM-utilization character among methylotrophic bacteria.
Collapse
Affiliation(s)
- M Schmid-Appert
- Mikrobiologisches Institut, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich, Switzerland
| | - K Zoller
- Mikrobiologisches Institut, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich, Switzerland
| | - H Traber
- Mikrobiologisches Institut, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich, Switzerland
| | - S Vuilleumier
- Mikrobiologisches Institut, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich, Switzerland
| | - T Leisinger
- Mikrobiologisches Institut, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich, Switzerland
| |
Collapse
|
24
|
Scharf B, Wittenberg R, Engelhard M. Electron transfer proteins from the haloalkaliphilic archaeon Natronobacterium pharaonis: possible components of the respiratory chain include cytochrome bc and a terminal oxidase cytochrome ba3. Biochemistry 1997; 36:4471-9. [PMID: 9109654 DOI: 10.1021/bi962312d] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Natronobacterium pharaonis, an aerobic haloalkaliphilic archaebacterium, expresses high concentrations of redox proteins as do alkaliphilic eubacteria. The first redox protein characterized from N. pharaonis was halocyanin [Scharf, B., & Engelhard, M. (1993) Biochemistry 32, 12894-12900], a small blue copper protein. It is a peripheral membrane protein and is conjectured to function in a manner similar to plastocyanin. In the present work, the respiratory chain is further elucidated and the purification and characterization of the most abundant components cytochrome bc and cytochrome ba3 from the membrane fraction are described. The cytochrome bc complex consists of a 14 and an 18 kDa subunit in a 1:1 ratio, with heme c bound to the larger polypeptide. An Fe-S subunit similar to that found in eukaryotic bc complexes has not yet been identified. The second membrane complex carries two different heme groups of the ba3-type as well as copper. It contains two subunits of 36 and 40 kDa. This cytochrome ba3 binds carbon monoxide, a feature common to terminal oxidases. There is no spectroscopic evidence for a second terminal oxidase; hence, under the growth conditions chosen the respiratory chain of N. pharaonis appears to be unbranched. In addition to these cytochromes, a succinate dehydrogenase which is solubilized from the membrane by detergents was isolated. A cytochrome c which was isolated from the cytosol has an unusually high molecular weight and a redox potential of -142 mV. A second cytosolic protein, ferredoxin, was purified to homogeneity. A comparison of the redox potentials of the isolated proteins with those obtained from the native membrane allows the construction of a possible electron transfer chain.
Collapse
Affiliation(s)
- B Scharf
- Max-Planck-Institut für molekulare Physiologie, Dortmund, Germany
| | | | | |
Collapse
|
25
|
Holmes ML, Scopes RK, Moritz RL, Simpson RJ, Englert C, Pfeifer F, Dyall-Smith ML. Purification and analysis of an extremely halophilic beta-galactosidase from Haloferax alicantei. Biochim Biophys Acta 1997; 1337:276-86. [PMID: 9048905 DOI: 10.1016/s0167-4838(96)00174-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
As a first step in the development of a reporter system for gene expression in halophilic archaea, a beta-galactosidase was purified 140-fold from Haloferax alicantei (previously phenon K, strain Aa2.2). An overproducing mutant was first isolated by UV mutagenesis and screening on agar plates containing X-Gal substrate. Cytoplasmic extracts of the mutant contained 25-fold higher enzyme levels than the parent. Purification of the active enzyme was greatly facilitated by the ability of sorbitol to stabilise enzyme activity in the absence of salt, which allowed conventional purification methods (e.g., ion-exchange chromatography) to be utilised. The enzyme was optimally active at 4 M NaCl and was estimated to be 180 +/- 20 kDa in size, consisting of two monomers (each 78 +/- 3 kDa). It cleaves several different beta-galactoside substrates such as ONP-Gal, X-Gal and lactulose, but not lactose, and also has beta-D-fucosidase activity. No beta-glucosidase, beta-arabinosidase or beta-xylosidase activity could be detected. The amino-acid sequence at the N-terminus and of four proteolytic products has been determined.
Collapse
Affiliation(s)
- M L Holmes
- Department of Microbiology, University of Melbourne, Parkville, Australia
| | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
Endoribonuclease RNase E appears to control the rate-limiting step that mediates the degradation of many mRNA species in bacteria. In this work, an RNase E-like activity in Archaea is described. An endoribonucleolytic activity from the extreme halophile Haloarcula marismortui showed the same RNA substrate specificity as the Escherichia coli RNase E and cross-reacted with a monoclonal antibody raised against E. coli RNase E. The archaeal RNase E activity was partially purified from the extreme halophilic cells and shown, contrary to the E. coli enzyme, to require a high salt concentration for cleavage specificity and stability. These data indicate that a halophilic RNA processing enzyme can specifically recognize and cleave mRNA from E. coli in an extremely salty environment (3 M KCI). Having recently been shown in mammalian cells (A. Wennborg, B. Sohlberg, D. Angerer, G. Klein, and A. von Gabain, Proc. Natl. Acad. Sci. USA 92:7322-7326, 1995), RNase E-like activity has now been identified in all three evolutionary domains: Archaea, Bacteria, and Eukarya. This strongly suggests that mRNA decay mechanisms are highly conserved despite quite different environmental conditions.
Collapse
Affiliation(s)
- B Franzetti
- Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, CEA-DSV-CNRS UPR 9015, Grenoble, France
| | | | | | | |
Collapse
|
27
|
Ferrer J, Pérez-Pomares F, Bonete MJ. NADP-glutamate dehydrogenase from the halophilic archaeon Haloferax mediterranei: enzyme purification, N-terminal sequence and stability. FEMS Microbiol Lett 1996; 141:59-63. [PMID: 9064251 DOI: 10.1111/j.1574-6968.1996.tb08363.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
An NADP(H)-specific glutamate dehydrogenase of Haloferax mediterranei has been purified to apparent homogeneity and characterised. The purified enzyme was stabilized by glycerol in absence of salt. Glutamate dehydrogenase from Hf. mediterranei is a hexameric enzyme with a native molecular mass of 320 kDa composed of monomers each with a molecular mass of 55 kDa. At pH 8.5 the enzyme has Kms of 0.018, 0.34 and 4.2 mM for NADP+, 2-oxoglutarate and ammonium, respectively. Amino acid composition and sequence of the first 16 residues of the N-terminus have been determined.
Collapse
Affiliation(s)
- J Ferrer
- División de Bioquímica, Facultad de Ciencias, Universidad de Alicante, Spain
| | | | | |
Collapse
|
28
|
Brinkmann H, Martin W. Higher-plant chloroplast and cytosolic 3-phosphoglycerate kinases: a case of endosymbiotic gene replacement. Plant Mol Biol 1996; 30:65-75. [PMID: 8616244 DOI: 10.1007/bf00017803] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Previous studies indicated that plant nuclear genes for chloroplast and cytosolic isoenzymes of 3-phosphoglycerate kinase (PGK) arose through recombination between a preexisting gene of the eukaryotic host nucleus for the cytosolic enzyme and an endosymbiont-derived gene for the chloroplast enzyme. We readdressed the evolution of eukaryotic pgk genes through isolation and characterisation of a pgk gene from the extreme halophilic, photosynthetic archaebacterium Haloarcula vallismortis and analysis of PGK sequences from the three urkingdoms. A very high calculated net negative charge of 63 for PGK from H. vallismortis was found which is suggested to result from selection for enzyme solubility in this extremely halophilic cytosol. We refute the recombination hypothesis proposed for the origin of plant PGK isoenzymes. The data indicate that the ancestral gene from which contemporary homologues for the Calvin cycle/glycolytic isoenzymes in higher plants derive was acquired by the nucleus from (endosymbiotic) eubacteria. Gene duplication subsequent to separation of Chlamydomonas and land plant lineages gave rise to the contemporary genes for chloroplast and cytosolic PGK isoenzymes in higher plants, and resulted in replacement of the preexisting gene for PGK of the eukaryotic cytosol. Evidence suggesting a eubacterial origin of plant genes for PGK via endosymbiotic gene replacement indicates that plant nuclear genomes are more highly chimaeric, i.e. contain more genes of eubacterial origin, than is generally assumed.
Collapse
Affiliation(s)
- H Brinkmann
- Institut für Botanik, Technische Universität Braunschweig, Germany
| | | |
Collapse
|
29
|
Bischoff KM, Rodwell VW. 3-Hydroxy-3-methylglutaryl-coenzyme A reductase from Haloferax volcanii: purification, characterization, and expression in Escherichia coli. J Bacteriol 1996; 178:19-23. [PMID: 8550415 PMCID: PMC177616 DOI: 10.1128/jb.178.1.19-23.1996] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Prior work from this laboratory characterized eukaryotic (hamster) and eubacterial (Pseudomonas mevalonii) 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductases. We report here the characterization of an HMG-CoA reductase from the third domain, the archaea. HMG-CoA reductase of the halobacterium Haloferax volcanii was initially partially purified from extracts of H. volcanii. Subsequently, a portion of the H. volcanii lovastatin (formerly called mevinolin) resistance marker mev was subcloned into the Escherichia coli expression vector pT7-7. While no HMG-CoA reductase activity was detectable following expression in E. coli, activity could be recovered after extracts were exposed to 3 M KCl. Following purification to electrophoretic homogeneity, the specific activity of the expressed enzyme, 24 microU/mg, equaled that of homogeneous hamster or P. mevalonii HMG-CoA reductase. Activity was optimal at pH 7.3. Kms were 66 microM (NADPH) and 60 microM [(S)-HMG-CoA]. (R)-HMG-CoA and lovastatin inhibited competitively with (S)-HMG-CoA. H. volcanii HMG-CoA reductase also catalyzed the reduction of mevaldehyde [optimal activity at pH 6.0; Vmax 11 microU/mg; Kms 32 microM (NADPH), 550 microM [(R,S)-mevaldehyde]] and the oxidative acylation of mevaldehyde [optimal activity at pH 8.0; Vmax 2.1 microU/mg; Kms 350 microM (NADP+), 300 microM (CoA), 470 microM [(R,S)-mevaldehyde]]. These properties are comparable to those of hamster and P. mevalonii HMG-CoA reductases, suggesting a similar catalytic mechanism.
Collapse
Affiliation(s)
- K M Bischoff
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153, USA
| | | |
Collapse
|
30
|
Camacho ML, Brown RA, Bonete MJ, Danson MJ, Hough DW. Isocitrate dehydrogenases from Haloferax volcanii and Sulfolobus solfataricus: enzyme purification, characterisation and N-terminal sequence. FEMS Microbiol Lett 1995; 134:85-90. [PMID: 8593959 DOI: 10.1111/j.1574-6968.1995.tb07919.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The isocitrate dehydrogenases from the extremely halophilic Archaeon, Haloferax volcanii, and from the hyperthermophilic Archaeon, Sulfolobus solfataricus, have been purified to electrophoretic homogeneity. The purified enzymes have been characterised with respect to their cofactor specificities, subunit compositions and their salt and thermal stabilities. N-terminal amino acid sequences have been determined for both enzymes, and multiple alignments with sequences of bacterial and eukaryotic isocitrate dehydrogenases show that the archaeal enzymes most closely resemble the NADP-linked dimeric isocitrate dehydrogenases from the Bacteria.
Collapse
Affiliation(s)
- M L Camacho
- División de Bioquímica, Facultad de Ciencias, Universidad de Alicante, Spain
| | | | | | | | | |
Collapse
|
31
|
Grosjean H, Constantinesco F, Foiret D, Benachenhou N. A novel enzymatic pathway leading to 1-methylinosine modification in Haloferax volcanii tRNA. Nucleic Acids Res 1995; 23:4312-9. [PMID: 7501451 PMCID: PMC307385 DOI: 10.1093/nar/23.21.4312] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Transfer RNAs of the extreme halophile Haloferax volcanii contain several modified nucleosides, among them 1-methylpseudouridine (m1 psi), pseudouridine (psi), 2'-0-methylcytosine (Cm) and 1-methylinosine (m1l), present in positions 54, 55, 56 and 57 of the psi-loop, respectively. At the same positions in tRNAs from eubacteria and eukaryotes, ribothymidine (T-54), pseudouridine (psi-55), non-modified cytosine (C-56) and non-modified adenosine or guanosine (A-57 or G-57) are found in the so-called T psi-loop. Using as substrate a T7 transcript of Haloferax volcanii tRNA(Ile) devoid of modified nucleosides, the enzymatic activities of several tRNA modification enzymes, including those for m1 psi-54, psi-55, Cm-56 and m1l-57, were detected in cell extracts of H.volcanii. Here, we demonstrate that modification of A-57 into m1l-57 in H.volcanii tRNA(Ile) occurs via a two-step enzymatic process. The first step corresponds to the formation of m1A-57 catalyzed by a S-adenosylmethionine-dependent tRNA methyltransferase, followed by the deamination of the 6-amino group of the adenine moiety by a 1-methyladenosine-57 deaminase. This enzymatic pathway differs from that leading to the formation of m1l-37 in the anticodon loop of eukaryotic tRNA(Ala). In the latter case, inosine-37 formation preceeds the S-adenosylmethionine-dependent methylation of l-37 into m1l-37. Thus, enzymatic strategies for catalyzing the formation of 1-methylinosine in tRNAs differ in organisms from distinct evolutionary kingdoms.
Collapse
Affiliation(s)
- H Grosjean
- Laboratoire d'Enzymologie et de Biochimie Structurales, CNRS, Gif-sur-Yvette, France
| | | | | | | |
Collapse
|
32
|
Abstract
D-Lactate is readily used as a substrate for the growth of species of halophilic archaea belonging to the genera Haloferax and Haloarcula. L-Lactate was used by Haloferax species (Haloferax volcanii, Haloferax mediterranei) only when a substantial concentration of the D-isomer was also present in the medium. On the enzymatic level, considerable diversity was found in the lactate metabolism of the different representatives of the Halobacteriaceae. At least three types of lactate dehydrogenases were detected in halophilic archaea. A high level of activity of an NAD-linked enzyme was present constitutively in Haloarcula species, and a low level of activity was also detected in Haloferax mediterranei. NAD-independent lactate dehydrogenases, oxidizing L-lactate and D-lactate with 2,6-dichlorophenol-indophenol as electron acceptor, were detected in all nine species tested, but L-lactate dehydrogenase activity in Halobacterium species was very low, and Haloarcula species, which possess a high level of activity of NAD-linked lactate dehydrogenase, showed very low activities of both NAD-independent D- and L-lactate dehydrogenase. An inducible lactate racemase, displaying an unusually high pH optimum, was found in Haloferax volcanii. Lactate racemase activity was found constitutively in Haloarcula species, but no activity was detected in Halobacterium species and in Haloferax mediterranei.
Collapse
Affiliation(s)
- A Oren
- Division of Microbial and Molecular Ecology, Alexander Silverman Institute of Life Sciences, Jerusalem, Israel
| | | |
Collapse
|
33
|
Oren A. Enzyme diversity in halophilic archaea. Microbiologia 1994; 10:217-28. [PMID: 7873098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The halophilic archaea display a considerable extent of enzyme diversity. The presence or absence of certain enzymatic activities is closely linked with the taxonomic status of the strains investigated. Thus, Halobacterium species such as Hb. salinarium, Hb. halobium, and Hb. cutirubrum differ from most other Halobacteriaceae tested by the possession of an NAD(+)-dependent glycerol dehydrogenase, by the absence of methylglyoxal synthase activity, and the ability of fermentative growth on arginine. Species such as Hb. saccharovorum and Hb. sodomense, which are still classified within the genus Halobacterium, have an enzymatic machinery greatly different from that of the Hb. salinarium-Hb. halobium group, confirming the need for a taxonomic reappraisal of these species. The presence of NAD(+)-dependent D-lactate dehydrogenase is characteristic of representatives of the genus Haloarcula, which possess only low activities of NAD(+)-independent L- and D-lactate dehydrogenases, if at all. Other enzymes which show considerable diversity are fructose 1,6-bisphosphate aldolase, of which two classes exist, and ribulose 1,6-bisphosphate carboxylase, which is present in a limited number of species.
Collapse
Affiliation(s)
- A Oren
- Division of Microbial and Molecular Ecology, Hebrew University of Jerusalem, Israel
| |
Collapse
|
34
|
Rangaswamy V, Altekar W. Ketohexokinase (ATP:D-fructose 1-phosphotransferase) from a halophilic archaebacterium, Haloarcula vallismortis: purification and properties. J Bacteriol 1994; 176:5505-12. [PMID: 8071229 PMCID: PMC196739 DOI: 10.1128/jb.176.17.5505-5512.1994] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Ketohexokinase (ATP:D-fructose 1-phosphotransferase [EC 2.7.1.3]), detected for the first time in a prokaryote, i.e., the extreme halophile Haloarcula vallismortis, was isolated and characterized from the same archaebacterium. This enzyme was characterized with respect to its molecular mass, amino acid composition, salt dependency, immunological cross-reactivity, and kinetic properties. Gel filtration and sucrose density gradient centrifugation revealed a native molecular mass of 100 kDa for halobacterial ketohexokinase, which is larger than its mammalian counterpart. The enzyme could be labeled by UV irradiation in the presence of [ gamma-32P]ATP, suggesting the involvement of a phosphoenzyme intermediate. Other catalytic features of the enzyme were similar to those of its mammalian counterparts. No antigenic cross-reactivity could be detected between the H. vallismortis ketohexokinase and the ketohexokinases from different rat tissues.
Collapse
Affiliation(s)
- V Rangaswamy
- Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India
| | | |
Collapse
|
35
|
Rajagopalan R, Altekar W. Characterisation and purification of ribulose-bisphosphate carboxylase from heterotrophically grown halophilic archaebacterium, Haloferax mediterranei. Eur J Biochem 1994; 221:863-9. [PMID: 8174567 DOI: 10.1111/j.1432-1033.1994.tb18801.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The CO2-fixing enzyme of Calvin cycle ribulose-1,5-bisphosphate-carboxylase/oxygenase has been isolated from a halophilic bacterium, Haloferax mediterranei grown heterotrophically. A homogeneous preparation was obtained from sonicated extract of the cells by three steps, resulting in a specific activity of 52 nmol.min-1.mg protein-1. The physicochemical and catalytic properties of the enzyme were studied. The halobacterial ribulose-bisphosphate carboxylase is an oligomer of 54-kDa and 14-kDa subunits as detected by SDS/PAGE. By sucrose-density-gradient centrifugation, the molecular mass of the enzyme was estimated as approximately 500 kDa indicating a hexadecameric nature. No evidence for an additional form of the enzyme devoid of small subunits was obtained. The enzyme required Mg2+ for activity, KCl for activity and stability, and an optimal pH of 7.8. In contrast to many halophilic proteins, ribulose-bisphosphate carboxylase from H. mediterranei is not an acidic protein. From the comparison of amino acid composition of halobacterial enzyme with its counterparts from a few eukaryotic and eubacterial sources, the S delta Q values showed that these proteins share some compositional similarities.
Collapse
Affiliation(s)
- R Rajagopalan
- Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India
| | | |
Collapse
|
36
|
Goldgur Y, Safro M. Aminoacyl-tRNA synthetases from Haloarcula marismortui: an evidence for a multienzyme complex in a procaryotic system. Biochem Mol Biol Int 1994; 32:1075-83. [PMID: 8061624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aminoacyl-tRNA synthetases in halophilic archaebacterium Haloarcula marismortui form a high molecular weight multienzyme complex which is resistant to dissociation when subjected to gel filtration, ion exchange, ammonium sulfate mediated and hydroxyapatite chromatography. Functional and structural aspects of the aminoacyl-tRNA synthetase complex formation are discussed.
Collapse
Affiliation(s)
- Y Goldgur
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | | |
Collapse
|
37
|
Abstract
A novel prenyltransferase, farnesylgeranyl diphosphate (FGPP) synthase (EC 2.5.1.X), which synthesizes C25-prenyl diphosphate, was found in the haloalkaliphilic archaeon Natronobacterium pharaonis. It was separated from geranylgeranyl diphosphate (GGPP) synthase (EC 2.5.1.29), which synthesizes C20-prenyl diphosphate, a major prenyltransferase in this organism. The highest activity of FGPP synthase was observed when GGPP was used as the allylic substrate. FGPP synthase may synthesize a precursor for the C25 moiety of C20, C25 diether lipids using a longer allylic diphosphate, such as GGPP synthesized by GGPP synthase, rather than dimethylallyl diphosphate, which is the product of isopentenyl diphosphate isomerase.
Collapse
Affiliation(s)
- A Tachibana
- Department of Biology, Faculty of Science, Osaka City University, Japan
| |
Collapse
|
38
|
Muriana FJ, Alvarez-Ossorio MC, Relimpio AM. Further thermal characterization of an aspartate aminotransferase from a halophilic organism. Biochem J 1994; 298 ( Pt 2):465-70. [PMID: 8135756 PMCID: PMC1137963 DOI: 10.1042/bj2980465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Aspartate aminotransferase (AspAT, EC 2.6.1.1) from the halophilic archaebacterium Haloferax mediterranei was purified [Muriana, Alvarez-Ossorio and Relimpio (1991) Biochem. J. 278, 149-154] and further characterization of the effects of temperature on the activity and stability of the halophilic AspAT were carried out. The halophilic transaminase is most active at 65 degrees C and stable at high temperatures, under physiological or nearly physiological conditions (3.5 M KCl, pH 7.8). Thermal inactivation (60-85 degrees C) of the halophilic AspAT followed first-order kinetics, 2-oxoglutarate causing a shift of the thermal inactivation curves to higher temperatures. The salt concentration affected the thermal stability of the halophilic transaminase at 60 degrees C, suggesting that disruption of hydrophobic interactions may play an important role in the decreased thermal stability of the enzyme.
Collapse
Affiliation(s)
- F J Muriana
- Department of Biochemistry, Faculty of Pharmacy, University of Seville, Spain
| | | | | |
Collapse
|
39
|
Blecher O, Goldman S, Mevarech M. High expression in Escherichia coli of the gene coding for dihydrofolate reductase of the extremely halophilic archaebacterium Haloferax volcanii. Reconstitution of the active enzyme and mutation studies. Eur J Biochem 1993; 216:199-203. [PMID: 8365406 DOI: 10.1111/j.1432-1033.1993.tb18133.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The gene coding for the enzyme dihydrofolate reductase of the extremely halophilic archaebacterium Haloferax volcanii was recombined into the Escherichia coli expression vector pET11d. Following induction, the enzyme was produced in large quantities and accumulated in the cells in an insoluble form. The enzymic activity could be efficiently reconstituted by dissolving the aggregate in 6 M guanidine hydrochloride followed by dilution into salt solutions. Mutants were produced in which Lys30 was converted to Leu (K30L), Lys31 was converted to Ala (K31A) and a double mutant in which both lysines were converted (K30L, K31A). The mutated enzymes were produced in E. coli, activated and purified to homogeneity. The effect of the salt concentration on the steady-state kinetic parameters was determined. It was found that the salt concentration affects the Km but not kcat of the various mutants.
Collapse
Affiliation(s)
- O Blecher
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
| | | | | |
Collapse
|
40
|
Kamekura M, Seno Y. Partial sequence of the gene for a serine protease from a halophilic archaeum Haloferax mediterranei R4, and nucleotide sequences of 16S rRNA encoding genes from several halophilic archaea. Experientia 1993; 49:503-13. [PMID: 8335078 DOI: 10.1007/bf01955152] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A part of the gene coding for a halophilic serine protease from a halophilic archaeum Haloferax mediterranei R4 was amplified by PCR and its 672 nucleotide sequence was determined. Tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172P1. Nucleotide sequences of 16S rRNA encoding genes from 9 halophilic archaea were determined. Alignment of 19 sequences known so far showed that there are more than 20 positions carrying bases or deletions specific for each halobacterial genus: Halobacterium, Haloarcula, Haloferax, and Halococcus.
Collapse
Affiliation(s)
- M Kamekura
- Noda Institute for Scientific Research, Chiba-ken, Japan
| | | |
Collapse
|
41
|
Prüss B, Meyer HE, Holldorf AW. Characterization of the glyceraldehyde 3-phosphate dehydrogenase from the extremely halophilic archaebacterium Haloarcula vallismortis. Arch Microbiol 1993; 160:5-11. [PMID: 8352651 DOI: 10.1007/bf00258139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) from the extremely halophilic archaebacterium Haloarcula vallismortis has been purified in a four step procedure to electrophoretic homogeneity. The enzyme is a tetramer with a relative molecular mass of 160,000. It is strictly NAD(+)-dependent and exhibits its highest activity in 2 mol/l KCl at 45 degrees C. Amino acid analysis and isoelectric focusing indicate an excess of acidic amino acids. Two parts of the primary sequence are reported. These peptides have been compared with glyceraldehyde 3-phosphate dehydrogenases from other archaebacteria, eubacteria and eucaryotes. The peptides show a high grade of similarity to glyceraldehyde 3-phosphate dehydrogenase from eucaryotes.
Collapse
Affiliation(s)
- B Prüss
- Institut für Physiologische Chemie, Ruhr-Universität Bochum, Germany
| | | | | |
Collapse
|
42
|
Vettakkorumakankav NN, Stevenson KJ. Dihydrolipoamide dehydrogenase from Haloferax volcanii: gene cloning, complete primary structure, and comparison to other dihydrolipoamide dehydrogenases. Biochem Cell Biol 1992; 70:656-63. [PMID: 1339281 DOI: 10.1139/o92-101] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We used the N-terminal amino acid sequence of dihydrolipoamide dehydrogenase from Haloferax volcanii, to design and synthesize two oligonucleotide probes that were used to identify and clone a 4.3 kilobase pair (kbp) fragment from MboI restriction endonuclease digestion of Hf. volcanii genomic DNA. The nucleotide sequence of a 1.5-kbp region of this clone was determined and this revealed an open reading frame that translated into a protein with good homology to dihydrolipoamide dehydrogenase from other sources. The first 48 amino acids were identical with the N-terminal sequence data obtained from the purified protein. The complete primary structure of the halophilic dihydrolipoamide dehydrogenase was analyzed in terms of its homologies to dihydrolipoamide dehydrogenases from other sources and its molecular adaptations to high intracellular ionic strength.
Collapse
|
43
|
Affiliation(s)
- K D James
- Department of Biochemistry, University of Bath, Claverton Down, U.K
| | | | | | | | | |
Collapse
|
44
|
Abstract
A membrane-bound nitrate reductase (nitrite:(acceptor) oxidoreductase, EC 1.7.99.4) from the extremely halophilic bacterium Haloferax denitrificans was solubilized by incubating membranes in buffer lacking NaCl and purified by DEAE, hydroxylapatite, and Sepharose 6B gel filtration chromatography. The purified nitrate reductase reduced chlorate and was inhibited by azide and cyanide. Preincubating the enzyme with cyanide increased the extent of inhibition which in turn was intensified when dithionite was present. Although cyanide was a noncompetitive inhibitor with respect to nitrate, nitrate protected against inhibition. The enzyme, as isolated, was composed of two subunits (Mr 116,000 and 60,000) and behaved as a dimer during gel filtration (Mr 380,000). Unlike other halobacterial enzymes, this nitrate reductase was most active, as well as stable, in the absence of salt.
Collapse
Affiliation(s)
- L I Hochstein
- Planetary Biology Branch, Ames Research Center, Moffett Field, California 94035
| | | |
Collapse
|
45
|
Abstract
Pure and absolutely DNA-dependent RNA polymerase has been isolated from the extremely halophilic archaebacterium, Halococcus morrhuae. It is composed of five heavy (142 000; 88 000; 73 000; 52 500; and 49 500 Da) and five small components (13 300; 11 200; 10 800; 10 500; 9 900 Da). The peptides of 49 500 Da and 52 500 Da probably represent one component in different modification states. Single-stranded DNA shows the highest template efficiency, although archaebacterial chromosomal DNAs are efficiently transcribed. Rifampicin, streptolydigin and alpha-amanitin do not inhibit transcription by this enzyme. Heparin permits elongation but not initiation of transcription. The activity of H. morrhuae RNA polymerase is strongly stimulated by glycerol and dimethylsulfoxide.
Collapse
|
46
|
Pundak S, Aloni H, Eisenberg H. Structure and activity of malate dehydrogenase from the extreme halophilic bacteria of the Dead Sea. 2. Inactivation, dissociation and unfolding at NaCl concentrations below 2 M. Salt, salt concentration and temperature dependence of enzyme stability. Eur J Biochem 1981; 118:471-7. [PMID: 7297557 DOI: 10.1111/j.1432-1033.1981.tb05543.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The stability of halophilic malate dehydrogenase increases with increasing salt concentration and with decrease in temperature. Stabilization by various salts, at high salt concentrations, follows the Hofmeister series. The enzyme inactivation rates closely match dissociation of the dimeric enzymes into monomeric subunits and unfolding of the polypeptide chains, as followed by velocity sedimentation, light scattering and circular dichroism measurements. The alpha-helix content goes to zero upon denaturation. Unusual water and salt binding properties of the native enzyme (cf. preceding paper, in this journal) are believed to be largely lost upon enzyme dissociation and unfolding. The properties thus seem to be associated with the intact structure of the enzyme.
Collapse
|
47
|
Pundak S, Eisenberg H. Structure and activity of malate dehydrogenase from the extreme halophilic bacteria of the Dead Sea. 1. Conformation and interaction with water and salt between 5 M and 1 M NaCl concentration. Eur J Biochem 1981; 118:463-70. [PMID: 7297556 DOI: 10.1111/j.1432-1033.1981.tb05542.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Large-scale growth of extreme halophilic bacteria from the Dead Sea and purification of malate dehydrogenase (and other proteins) in quantities of hundreds of milligrams makes possible a detailed study of the adaptation to high salt. Halophilic malate dehydrogenase is stable at 20 degrees C in NaCl solutions between 2.5--5 M. Below 2.5 M NaCl time-dependent inactivation, paralleled by structural changes, sets in. Within the time scale of the sedimentation, diffusion and circular dichroism experiments discussed here, it was possible to analyze data corresponding to the active halophilic malate dehydrogenase between 1 M and 5 M NaCl. The striking observation was that rather minor conformation changes were observed over the whole range, yet the special properties of the halophilic enzyme seem to be related to its capacity of associating with unusually large amounts of water and of salts, quite distinct from non-halophilic counterparts. These special properties seem to be related to the intact structure of the protein. Some parallel properties of halophilic glutamate dehydrogenase are also discussed.
Collapse
|