Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

[reaction: see text] Biotransformations of a number of differently substituted and configured oxiranecarbonitriles using Rhodococcus sp. AJ270, a microbial whole-cell catalyst that contains nitrile hydratase/amidase, were studied. While almost all trans-configured 3-aryl-2-methyloxiranecarbonitriles and 2,3-dimethyl-3-phenyloxiranecarbonitrile were efficiently hydrated by the action of the less enantioselective nitrile hydratase, the amidase exhibited excellent 2S,3R-enantioselectivity against 2-methyl-3-(para-substituted-phenyl)oxiranecarboxamides. Under very mild conditions, biotransformations of nitriles provided an efficient and practical synthesis of 2R,3S-(-)-3-aryl-2-methyloxiranecarboxamides, electrophilic epoxides with tertiary and quaternary stereocenters, in excellent yield with enantiomeric excess greater than 99.5%. The synthetic applications of the resulting enantiomerically pure epoxides were demonstrated by convenient and straightforward syntheses of polyfunctionalized chiral molecules possessing a quaternary stereocenter such as R-(+)-2-hydroxy-2-methyl-3-phenylpropionic acid, 2R,3R-(-)-3-amino-2-hydroxy-2-methyl-3-phenylpropionic acid, and 2S,3S-(+)-2-amino-3-hydroxy-2-methyl-3-phenylpropionic acid, employing the regio- and stereospecific epoxide ring opening reactions of 2R,3S-(-)-2-methyl-3-phenyloxiranecarboxamide as the key steps.
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PMID:Nitrile biotransformations for highly enantioselective synthesis of oxiranecarboxamides with tertiary and quaternary stereocenters; efficient chemoenzymatic approaches to enantiopure alpha-methylated serine and isoserine derivatives. 1578 29

The nitrile metabolising strains AJ270, AJ300 and AJ115 were isolated from the same location. The strains have very similar nitrile metabolising profiles. Sequencing of the 16S rRNA gene indicates that strains AJ270 and AJ300 are novel strains of Rhodococcus erythropolis while strain AJ115 is a novel Microbacterium strain very closely related to Microbacterium oxydans and Microbacterium liquefaciens. Analysis of the structure of the nitrile hydratase/amidase gene clusters in the three strains indicates that this region is identical in these strains and that this structure is different to other nitrile hydratase/amidase gene clusters. The major difference seen is the insertion of a complete copy of the insertion sequence IS1166 in the nhr2 gene. This copy of IS1166 generates a 10 bp direct duplication at the point of insertion and has one ORF encoding a protein of 434 amino acids, with 98% homology to the transposase of IS666 from Mycobacterium avium. A gene oxd, encoding aldoxime dehydratase is found upstream of the nitrile hydratase gene cluster and an open reading frame encoding a protein with homology to GlnQ type ABC transporters is found downstream of the nitrile hydratase/amidase genes. The identity of the nitrile hydratase/amidase gene clusters in the three strains suggests horizontal gene transfer of this region. Analysis of the strains for both linear and circular plasmids indicates that both are present in the strains but hybridisation studies indicate that the nitrile hydratase/amidase gene cluster is chromosomally located. The nitrile hydratase/amidase enzymes of strain AJ270 are inducible with acetonitrile or acetamide. Interestingly although a number of Fe-type nitrile hydratases have been shown to be photosensitive, the enzyme from strain AJ270 is not.
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PMID:Characterisation of the nitrile hydratase gene clusters of Rhodococcus erythropolis strains AJ270 and AJ300 and Microbacterium sp. AJ115 indicates horizontal gene transfer and reveals an insertion of IS1166. 1580 88

The gene cluster containing the nitrile hydratase (NHase) and amidase genes of a moderate thermophile, B. pallidus RAPc8 has been cloned and sequenced. The (5.9 kb) section of cloned DNA contained eight complete open reading frames, encoding (in order), amidase (belonging to the nitrilase related aliphatic amidase family), nitrile hydratase beta and alpha subunits (of the cobalt containing class), a 122-amino acid accessory protein, designated P14K, a homologue of the 2Fe-2S class of ferredoxins and three putative proteins with distinct homology to the cobalt uptake proteins cbiM, cbiN and cbiQ of the S. typhimurium LT2 cobalamin biosynthesis pathway. The amidase and nitrile hydratase genes were subcloned and inducibly expressed in Escherichia coli, to levels of approximately 37 U/mg and 49 U/mg, respectively, without the co-expression of additional flanking genes. However, co-expression of P14K with the NHase structural genes significantly enhanced the specific activity of the recombinant NHase. This is the first description of an accessory protein involved in thermostable NHase expression. Modelling of the P14K protein structure has suggested that this protein functions as a subunit-specific chaperone, aiding in the folding of the NHase alpha subunit prior to alpha-beta subunit association and the formation of alpha(2)beta(2) NHase holoenzyme.
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PMID:Molecular analysis of the nitrile catabolism operon of the thermophile Bacillus pallidus RAPc8. 1595 32

A gene cluster responsible for aldoxime metabolism in the glutaronitrile degrader Pseudomonas sp. K-9 was analyzed genetically and enzymatically. The cluster was composed of genes coding for aldoxime dehydratase (Oxd), nitrile hydratase (NHase), NHase activator, amidase, acyl-CoA ligase, and some regulatory and functionally unknown proteins, which were similar to proteins appearing in the "aldoxime-nitrile pathway" gene cluster from strains having Fe-containing NHase. A key enzyme in the cluster, OxdK, which has 32.7-90.3 % identity with known Oxds, was overexpressed in Escherichia coli cells under the control of a T7 promoter in its His(6)-tagged form, purified, and characterized. The enzyme showed similar characteristics with the known Oxds coexisting with an Fe-containing NHase in its subunit structure, substrate specificity, and effects on various compounds. The enzyme can be classified into a group of "aliphatic aldoxime dehydratase (EC 4.99.1.5)." The existence of a gene cluster of enzymes responsible for aldoxime metabolism via the aldoxime-nitrile pathway (aldoxime-->nitrile-->amide-->acid-->acyl-CoA) in Pseudomonas sp. K-9, and the fact that the proteins comprising the cluster are similar to those acting on aliphatic type substrates, evidently clarified the alkylaldoxime-degrading pathway in that strain.
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PMID:Molecular and enzymatic analysis of the "aldoxime-nitrile pathway" in the glutaronitrile degrader Pseudomonas sp. K-9. 1600 57

We identified an aldoxime dehydratase (Oxd) gene in the 5'-flanking region of the nitrile hydratase-amidase gene cluster in the photoreactive iron-type nitrile hydratase-producer, Rhodococcus sp. N-771. The enzyme showed 96.3%, 77.6%, and 30.4% identities with the Oxds of Rhodococcus globerulus A-4, Pseudomonas chlororaphis B23, and Bacillus sp. OxB-1, respectively. The enzyme was expressed in Escherichia coli under the control of the lac- or T7 promoters in its intact and His6-tagged forms, purified, and characterized. The enzyme had heme b as a prosthetic group, catalyzed a stoichiometric dehydration of aldoxime into nitrile, and exhibited the highest activity at neutral pH and at around 30 degrees C similar to the known Oxd from Bacillus sp. OxB-1. The activity was enhanced by reducing agents, such as Na2S, Na2S2(O4), 2-mercaptoethanol, and L-cysteine and supplementary additions of electron acceptors such as flavins, sulfite ion, and vitamin K3. The effect of various chemicals on the enzyme activity was different in the presence and absence of the reducing reagent, Na2S. The enzyme preferentially acts on aliphatic-type substrates and the substrate specificity of the enzyme coincides with that reported for nitrile hydratase produced by the strain.
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PMID:Aldoxime dehydratase co-existing with nitrile hydratase and amidase in the iron-type nitrile hydratase-producer Rhodococcus sp. N-771. 1623 24

A versatile nitrile-degrading bacterium was isolated by enrichment culture from the soil of a forest near Manali, Himachal Pradesh, India, and was identified as Nocardia globerula. This organism contains 3 enzymes with nitrile-degrading activity: nitrilase, nitrile hydratase, and amidase. Nocardia globerula NHB-2 cells grown on nutrient broth supplemented with 1% glucose and 0.1% yeast extract exhibited nitrile hydratase-amidase activity specific for saturated aliphatic nitriles or amide, while addition of acetonitrile in nutrient broth yielded cells with nitrile hydratase-amidase that in addition to saturated aliphatic nitriles-amide also hydrolyzed aromatic amide. Nocardia globerula NHB-2 cultivated on nutrient broth containing propionitrile exhibited nitrilase activity that hydrolyzed aromatic nitrile and unsaturated aliphatic nitrile. The versatility of this organism in the hydrolysis of various nitriles and amides makes it a potential bioresource for use in organic synthesis.
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PMID:Nocardia globerula NHB-2: a versatile nitrile-degrading organism. 1623 68

A bacterium capable of utilizing high concentrations of acetonitrile as the sole source of carbon and nitrogen was isolated from soil and identified as Pseudomonas putida. This bacterium could also utilize butyronitrile, glutaronitrile, isobutyronitrile, methacrylonitrile, propionitrile, succinonitrile, valeronitrile, and some of their corresponding amides, such as acetamide, butyramide, isobutyramide, methacrylamide, propionamide, and succinamide as growth substrates. Acetonitrile-grown cells oxidized acetonitrile with a K(m) of 40.61 mM. Mass balance studies with [C]acetonitrile indicated that nearly 66% of carbon of acetonitrile was released as CO(2) and 14% was associated with the biomass. Metabolites of acetonitrile in the culture medium were acetic acid and ammonia. The acetate formed in the early stages of growth completely disappeared in the later stages. Cell extracts of acetonitrile-grown cells contained activities corresponding to nitrile hydratase and amidase, which mediate the breakdown of actonitrile into acetic acid and ammonia. Both enzymes were intracellular and inducible and hydrolyzed a wide range of substrates. The specific activity of amidase was at least 150-fold higher than the activity of the enzyme nitrile hydratase.
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PMID:Degradation of Acetonitrile by Pseudomonas putida. 1634 8

This study aimed to construct an acetonitrile-containing waste treatment process by using nitrile-degrading microorganisms. To degrade high concentrations of acetonitrile, the microorganisms were newly acquired from soil and water samples. Although no nitrilase-producing microorganisms were found to be capable of degrading high concentrations of acetonitrile, the resting cells of Rhodococcus pyridinivorans S85-2 containing nitrile hydratase could degrade acetonitrile at concentrations as high as 6 M. In addition, an amidase-producing bacterium, Brevundimonas diminuta AM10-C-1, of which the resting cells degraded 6 M acetamide, was isolated. The combination of R. pyridinivorans S85-2 and B. diminuta AM10-C-1 was tested for the conversion of acetonitrile into acetic acid. The resting cells of B. diminuta AM10-C-1 were added after the first conversion involving R. pyridinivorans S85-2. Through this tandem process, 6 M acetonitrile was converted to acetic acid at a conversion rate of >90% in 10 h. This concise procedure will be suitable for practical use in the treatment of acetonitrile-containing wastes on-site.
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PMID:Convenient treatment of acetonitrile-containing wastes using the tandem combination of nitrile hydratase and amidase-producing microorganisms. 1640 66

In soil the herbicide 2,6-dichlorobenzonitrile (dichlobenil) is degraded to the persistent metabolite 2,6-dichlorobenzamide (BAM) which has been detected in 19% of samples taken from Danish groundwater. We tested if common soil bacteria harbouring nitrile-degrading enzymes, nitrile hydratases or nitrilases, were able to degrade dichlobenil in vitro. We showed that several strains degraded dichlobenil stoichiometrically to BAM in 1.5-6.0 days; formation of the amide intermediate thus showed nitrile hydratase rather than nitrilase activity, which would result in formation of 2,6-dichlorobenzoic acid. The non-halogenated analogue benzonitrile was also degraded, but here the benzamide intermediate accumulated only transiently showing nitrile hydratase followed by amidase activity. We conclude that a potential for dichlobenil degradation to BAM is found commonly in soil bacteria, whereas further degradation of the BAM intermediate could not be demonstrated.
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PMID:Transformation of the herbicide 2,6-dichlorobenzonitrile to the persistent metabolite 2,6-dichlorobenzamide (BAM) by soil bacteria known to harbour nitrile hydratase or nitrilase. 1649 93

The amidase gene from Rhodococcus rhodochrous M18 was cloned by PCR amplification with primers developed by use of peptide amino acid sequences obtained after treating amidase with trypsin. Nucleotide sequence analysis of this gene revealed high homology with aliphatic amidases from R. erythropolis R312 and Pseudomonas aeruginosa. Considering the substrate specificity and the results of DNA analysis, amidase from R. rhodochrous M8 was assigned to the group of aliphatic amidases preferentially hydrolyzing short-chain aliphatic amides. The amidase gene was expressed in cells of Escherichia coli from the self promoter and from the lac promoter. To clone a fragment of R. rhodochrous M8 chromosome (approximately 9 kb), containing the entire structural gene and its flanking regions, plasmid pRY1 that can be integrated into the chromosome via homology regions was used. No sequences of the nitrile hydratase gene, the second key gene of nitrile degradation in strain R. rhodochrous M8, were detected. Thus, genes encoding amidase and nitrile hydratase in strain R. rhodochrous M8 are not organized into a single operon despite their common regulation.
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PMID:[Cloning the amidase gene from Rhodococcus rhodochrous M18 and its expression in Escherichia coli]. 1702 57


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