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)

The D-serine deaminase structural (dsdA) and regulatory (dsdC) genes are transcribed with opposite polarity from an intergenic region comprising more than 600 base pairs. The order of genes in the dsd region is supN-dsdA-dsdC-aroC---his. The DNA sequence of the intergenic region has been slightly revised from a previously published version (E. McFall and L. Runkel, J. Bacteriol. 154:1508-1512, 1983). The dsdA gene is preceded by a long open reading frame. The dsdA in vivo transcription start sites for the wild type (base pair +1) and for three phenotypically distinct promoter constitutive mutants were determined by the S1 nuclease method. They are identical and are located about 81 base pairs upstream of the translation start site. D-Serine deaminase regulation is normal in rho mutants. Possible mechanisms for dsdA activation are discussed.
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PMID:In vivo D-serine deaminase transcription start sites in wild-type Escherichia coli and in dsdA promoter mutants. 302 15

The enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACPC deaminase) from a pseudomonad is a pyridoxal phosphate (PLP) linked catalyst which fragments the cyclopropane substrate to alpha-ketobutyrate and ammonia [Honma, M., & Shimomura, T. (1978) Agric. Biol. Chem. 42, 1825]. Enzymatic incubations in D2O yield alpha-ketobutyrate with one deuterium at the C-4 methyl group and one deuterium at one of the C-3 prochiral methylene hydrogens. Stereochemical analysis of the location of the C-3 deuteron was accomplished by in situ enzymatic reduction to (2S)-2-hydroxybutyrate with L-lactate dehydrogenase and conversion to the phenacyl ester. The C-3 hydrogens of the (2S)-2-hydroxybutyryl moiety are fully resolved in a 250-MHz NMR spectrum. Absolute assignment of 3S and 3R loci was obtained with phenacyl (2S,3S)-2-hydroxy[3-2H]butyrate generated enzymatically by D-serine dehydratase action on D-threonine. ACPC deaminase shows a stereoselective outcome with a 3R:3S deuterated product ratio of 72:28. 2-Vinyl-ACPC is also a fragmentation substrate with exclusive regiospecific cleavage to yield the straight-chain keto acid product 2-keto-5-hexenoate. The D isomer of vinylglycine is processed to alpha-ketobutyrate and ammonia at 8% the Vmax of ACPC, while L-vinylglycine is not a substrate. It is likely that ACPC and D-vinylglycine yield a common intermediate--the vinylglycine-PLP-p-quinoid adduct--which is then protonated sequentially at C-4 and then C-3 to account for the observed deuterium incorporation. The D isomers of beta-substituted alanines (fluoroalanine, chloroalanine, and O-acetyl-D-serine) partition between catalytic elimination and enzyme inactivation. Each shows a different partition ratio, arguing against the common aminoacrylyl-PLP as the inactivating species.
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PMID:Mechanistic studies on the pyridoxal phosphate enzyme 1-aminocyclopropane-1-carboxylate deaminase from Pseudomonas sp. 732 43