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)

A thermostable N-carbamoyl-D-amino acid amidohydrolase was found in the cells of newly isolated bacterium. Blastobacter sp. A17p-4. The bacterium also showed D-specific hydantoinase activity. The N-carbamoyl-D-amino acid amidohydrolase activity of the cells exhibited a temperature optimum at 50-55 degrees C, and was stable up to 50 degrees C. The N-carbamoyl-D-amino acid amidohydrolase of Blastobacter sp. A17p-4 was purified to homogeneity and characterized. It has a relative molecular weight of about 120,000 and consists of three identical subunits with a relative molecular weight of about 40,000. N-Carbamoyl-D-amino acids having hydrophobic groups served as good substrates for the enzyme. It has been suggested that D-amino acid production from DL-5-substituted hydantoin involves the action of a series of enzymes involved in pyrimidine degradation, namely amide-ring opening enzyme, dihydropyrimidinase, and N-carbamoylamide hydrolyzing enzyme, beta-ureidopropionase. However, the purified enzyme did not hydrolyze beta-ureidopropionate; suggesting that the N-carbamoyl-D-amino acid amidohydrolase coexisting with D-specific hydantoinase, probably dihydropyrimidinase, in Blastobacter sp. A17p-4 is different from beta-ureidopropionase.
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PMID:Thermostable N-carbamoyl-D-amino acid amidohydrolase: screening, purification and characterization. 776 78

The biocatalytic conversion of 5-mono-substituted hydantoins to the corresponding D-amino acids or L-amino acids involves first the hydrolysis of hydantoin to a N-carbamoylamino acid by an hydantoinase or dihydropyrimidinase, followed by the conversion of the N-carbamoylamino acid to the amino acid by N-carbamylamino acid amidohydrolase ( N-carbamoylase). Pseudomonas putida strain RU-KM3S, with high levels of hydantoin-hydrolysing activity, has been shown to exhibit non-stereoselective hydantoinase and L-selective N-carbamoylase activity. This study focused on identifying the hydantoinase and N-carbamoylase-encoding genes in this strain, using transposon mutagenesis and selection for altered growth phenotypes on minimal medium with hydantoin as a nitrogen source. Insertional inactivation of two genes, dhp and bup, encoding a dihydropyrimidinase and beta-ureidopropionase, respectively, resulted in loss of hydantoinase and N-carbamoylase activity, indicating that these gene products were responsible for hydantoin hydrolysis in this strain. dhp and bup are linked to an open reading frame encoding a putative transport protein, which probably shares a promoter with bup. Two mutant strains were isolated with increased levels of dihydropyrimidinase but not beta-ureidopropionase activity. Transposon mutants in which key elements of the nitrogen regulatory pathway were inactivated were unable to utilize hydantoin or uracil as a nitrogen source. However, these mutations had no effect on either the dihydropyrimidinase or beta-ureidopropionase activity. Disruption of the gene encoding dihydrolipoamide succinyltransferase resulted in a significant reduction in the activity of both enzymes, suggesting a role for carbon catabolite repression in the regulation of hydantoin hydrolysis in P. putida RU-KM3S cells.
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PMID:Mutational analysis of the hydantoin hydrolysis pathway in Pseudomonas putida RU-KM3S. 1506 75

A novel amidase acting on (R,S)-piperazine-2-tert-butylcarboxamide was purified from Pseudomonas sp. MCI3434 and characterized. The enzyme acted R-stereoselectively on (R,S)-piperazine-2-tert-butylcarboxamide to yield (R)-piperazine-2-carboxylic acid, and was tentatively named R-amidase. The N-terminal amino acid sequence of the enzyme showed high sequence identity with that deduced from a gene named PA3598 encoding a hypothetical hydrolase in Pseudomonas aeruginosa PAO1. The gene encoding R-amidase was cloned from the genomic DNA of Pseudomonas sp. MCI3434 and sequenced. Analysis of 1332 bp of the genomic DNA revealed the presence of one open reading frame (ramA) which encodes the R-amidase. This enzyme, RamA, is composed of 274 amino acid residues (molecular mass, 30 128 Da), and the deduced amino acid sequence exhibits homology to a carbon-nitrogen hydrolase protein (PP3846) from Pseudomonas putida strain KT2440 (72.6% identity) and PA3598 protein from P. aeruginosa strain PAO1 (65.6% identity) and may be classified into a new subfamily in the carbon-nitrogen hydrolase family consisting of aliphatic amidase, beta-ureidopropionase, carbamylase, nitrilase, and so on. The amount of R-amidase in the supernatant of the sonicated cell-free extract of an Escherichia coli transformant overexpressing the ramA gene was about 30 000 times higher than that of Pseudomonas sp. MCI3434. The intact cells of the E. coli transformant could be used for the R-stereoselective hydrolysis of racemic piperazine-2-tert-butylcarboxamide. The recombinant enzyme was purified to electrophoretic homogeneity from cell-free extract of the E. coli transformant overexpressing the ramA gene. On gel-filtration chromatography, the enzyme appeared to be a monomer. It had maximal activity at 45 degrees C and pH 8.0, and was completely inactivated in the presence of p-chloromercuribenzoate, N-ethylmaleimide, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, or Pb2+. RamA had hydrolyzing activity toward the carboxamide compounds, in which amino or imino group is connected to beta- or gamma-carbon, such as beta-alaninamide, (R)-piperazine-2-carboxamide (R)-piperidine-3-carboxamide, D-glutaminamide and (R)-piperazine-2-tert-butylcarboxamide. The enzyme, however, did not act on the other amide substrates for the aliphatic amidase despite its sequence similarity to RamA.
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PMID:A novel R-stereoselective amidase from Pseudomonas sp. MCI3434 acting on piperazine-2-tert-butylcarboxamide. 1506 83