Characterization of the Genes for the Biosynthesis of the Compatible Solute Ectoine in the Moderately Halophilic Bacterium Halomonas elongata DSM 3043

Cánovas, David; Vargas, Carmen Regla; Calderón, M.I.; Ventosa, António; Nieto, Joaquín J.

doi:10.1016/s0723-2020(98)80060-x

Cited by 93 publications

(52 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Ectoine is a compatible solute produced by several halophilic bacteria (11,31,39). Some of these are soil bacteria which could be considered potential ectoine suppliers for S. meliloti.…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, some bacteria can synthesize glycine betaine from carnitine (30,38,44). Ectoine is synthesized predominantly by halophilic bacteria, and to our knowledge there is no report on its production by either archaea or eukaryotes (11,31,39,42). This imino acid is produced from L-aspartate-␤-semialdehyde in a three step reaction, with L-2,4-diaminobutyrate and N␥-acetyl-L-2,4-diaminobutyrate as the intermediates (50).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Ectoine-Induced Proteins in Sinorhizobium meliloti Include an Ectoine ABC-Type Transporter Involved in Osmoprotection and Ectoine Catabolism

et al. 2005

View full text Add to dashboard Cite

To understand the mechanisms of ectoine-induced osmoprotection in Sinorhizobium meliloti, a proteomic examination of S. meliloti cells grown in minimal medium supplemented with ectoine was undertaken. This revealed the induction of 10 proteins. The protein products of eight genes were identified by using matrixassisted laser desorption ionization-time-of-flight mass spectrometry. Five of these genes, with four other genes whose products were not detected on two-dimensional gels, belong to the same gene cluster, which is localized on the pSymB megaplasmid. Four of the nine genes encode the characteristic components of an ATP-binding cassette transporter that was named ehu, for ectoine/hydroxyectoine uptake. This transporter was encoded by four genes (ehuA, ehuB, ehuC, and ehuD) that formed an operon with another gene cluster that contains five genes, named eutABCDE for ectoine utilization. On the basis of sequence homologies, eutABCDE encode enzymes with putative and hypothetical functions in ectoine catabolism. Analysis of the properties of ehuA and eutA mutants suggests that S. meliloti possesses at least one additional ectoine catabolic pathway as well as a lower-affinity transport system for ectoine and hydroxyectoine. The expression of ehuB, as determined by measurements of UidA activity, was shown to be induced by ectoine and hydroxyectoine but not by glycine betaine or by high osmolality.

show abstract

“…Ectoine is a compatible solute produced by several halophilic bacteria (11,31,39). Some of these are soil bacteria which could be considered potential ectoine suppliers for S. meliloti.…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Ectoine-Induced Proteins in Sinorhizobium meliloti Include an Ectoine ABC-Type Transporter Involved in Osmoprotection and Ectoine Catabolism

et al. 2005

View full text Add to dashboard Cite

show abstract

“…4A) (40,42). Enzymological studies (40) and the cloning of the ectoine biosynthetic genes (ectABC) from the gram-negative bacteria C. salexigens and H. elongata (11,22) and the gram-positive bacterium M. halophilus (37) have demonstrated the involvement of three enzymes (EctABC) in the production of this compatible solute. DNA sequence analysis of the ectoine biosynthetic genes of B. pasteurii carried out by us revealed the presence of highly related ectABC genes in this genus as well, suggesting that all ectoine-producing Bacilli use the same pathway to synthesize ectoine under high-osmolality growth conditions.…”

Section: Discussionmentioning

confidence: 99%

Osmotically Regulated Synthesis of the Compatible Solute Ectoine in Bacillus pasteurii and Related Bacillus spp

Kuhlmann

Bremer

2002

Appl Environ Microbiol

197

215

View full text Add to dashboard Cite

By using natural-abundance 13 C-nuclear magnetic resonance spectroscopy and high-performance liquid chromatography (HPLC) analysis we have investigated the types of compatible solutes that are synthesized de novo in a variety of Bacillus species under high-osmolality growth conditions. Five different patterns of compatible solute production were found among the 13 Bacillus species we studied. Bacillus subtilis, B. licheniformis, and B. megaterium produced proline; B. cereus, B. circulans, B. thuringiensis, Paenibacillus polymyxa, and Aneurinibacillus aneurinilyticus synthesized glutamate; B. alcalophilus, B. psychrophilus, and B. pasteurii synthesized ectoine; and Salibacillus (formerly Bacillus) salexigens produced both ectoine and hydroxyectoine, whereas Virgibacillus (formerly Bacillus) pantothenticus synthesized both ectoine and proline. Hence, the ability to produce the tetrahydropyrimidine ectoine under hyperosmotic growth conditions is widespread within the genus Bacillus and closely related taxa. To study ectoine biosynthesis within the group of Bacillus species in greater detail, we focused on B. pasteurii. We cloned and sequenced its ectoine biosynthetic genes (ectABC). The ectABC genes encode the diaminobutyric acid acetyltransferase (EctA), the diaminobutyric acid aminotransferase (EctB), and the ectoine synthase (EctC). Together these proteins constitute the ectoine biosynthetic pathway, and their heterologous expression in B. subtilis led to the production of ectoine. Northern blot analysis demonstrated that the ectABC genes are genetically organized as an operon whose expression is strongly enhanced when the osmolality of the growth medium is raised. Primer extension analysis allowed us to pinpoint the osmoregulated promoter of the B. pasteurii ectABC gene cluster. HPLC analysis of osmotically challenged B. pasteurii cells revealed that ectoine production within this bacterium is finely tuned and closely correlated with the osmolality of the growth medium. These observations together with the osmotic control of ectABC transcription suggest that the de novo synthesis of ectoine is an important facet in the cellular adaptation of B. pasteurii to high-osmolarity surroundings.

show abstract

“…1) and involves three special enzymes: Diaminobutyric Acid (DABA) aminotransferase (EctB) that catalyses amination of aspartate semialdehyde into diaminobutyric acid, DABA acetyltransferase (EctA) acetylating DABA into Nγ-acetyl diaminobutyric acid and ectoine synthase (EctC) that forms ectoine by cycling of Nγ-acetyl diaminobutyric acid (Peters et al, 1990). In various halophilic bacteria studied, the genes coding for the enzymes form a cluster ectABC (Canovas et al, 1998;Louis and Galinski, 1997;Goller et al, 1998;Kuhlmann and Bremer, 2002). Some bacteria possess an additional enzyme that converts ectoine to hydroxyectoine (ectoine hydroxylase, encoded by ectD) (Canovas et al, 1999;Prabhu et al, 2004;Bursy et al, 2007).…”

Section: Genetic Aspects Of Ectoine Biosynthesismentioning

confidence: 99%

Genetic and Biochemical Aspects of Ectoine Biosynthesis in Moderately Halophilic and Halotolerant Methylotrophic Bacteria

Khmelenina

Mustakhimov

Reshetnikov

et al. 2010

American Journal of Agricultural and Biological Sciences

View full text Add to dashboard Cite

Problem statement:The cyclic imino acid ectoine is a widely distributed compatible solute synthesizing by halophilic and halotolerant bacteria to prevent osmotic stress at high external salinity. This water-keeping compound is used in a variety of commercial cosmetics and therapeutic products. Approach: Development of integrated, predictive functional model of the metabolic and regulatory netwoks of ectoine-producing microbes is an active area of research. In this article we present a brief overview of the current knowledge on genetic and biochemical aspects of ectoine biosynthesis in aerobic halophilic and halotolerant bacteria utilizing C 1 compounds (methylotrophs). Although enzymology and genetics of the ectoine biosynthesis in methylotrophs are similar to other halophilic bacteria, the regulatory patterns are different. In all methylotrophic bacteria studied, the genes coding for specific enzymes of ectoine biosynthesis: Diaminobutyric Acid (DABA) aminotransferase (EctB), DABA acetyltransferase (EctA) and ectoine synthase (EctC) are organized into ectABC or ectABC-ask, whith is linked to gene encoding Aspartokinase isozyme (Ask). Results: Remarkably, the methylotrophic bacteria possessing a four-gene cluster showed higher halotolerance and accumulated more ectoine than bacteria with a cluster composed of three genes. The DABA acetyltransferases from three methylotrophic species have been comparatively characterized. The properties of the enzymes correlate with eco-physiological and metabolic particularities of the host. Some elements of the regulatory system governing the ectoine pathway operation have been revealed in both methane and methanol utilizing bacteria. In Methylomicrobium alcaliphilum transcription of the ectABC-ask operon is initiated from two σ 70 -like promoters and controlled by the EctR, a MarR-type negative regulator. EctR orthologs were identified in genomes of several heterotrophic halophilic bacteria. Here we present genomic data indicating that similar regulatory system may occur in diverse halophilic and halotolerant bacteria. Conclusion: Currently available data suggest that in methylotrophic bacteria the ectoine biosynthesis pathways are evolutionary well conserved, particularly with respect to the genes and enzymes involved. However, some differences in the ect-gene cluster organization and regulation could be observed.

show abstract

Characterization of the Genes for the Biosynthesis of the Compatible Solute Ectoine in the Moderately Halophilic Bacterium Halomonas elongata DSM 3043

Cited by 93 publications

References 33 publications

Ectoine-Induced Proteins in Sinorhizobium meliloti Include an Ectoine ABC-Type Transporter Involved in Osmoprotection and Ectoine Catabolism

Ectoine-Induced Proteins in Sinorhizobium meliloti Include an Ectoine ABC-Type Transporter Involved in Osmoprotection and Ectoine Catabolism

Osmotically Regulated Synthesis of the Compatible Solute Ectoine in Bacillus pasteurii and Related Bacillus spp

Genetic and Biochemical Aspects of Ectoine Biosynthesis in Moderately Halophilic and Halotolerant Methylotrophic Bacteria

Contact Info

Product

Resources

About