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)

DL-2-amino-Delta(2)-thiazolin-4-carbonic acid (DL-ATC) is a substrate for cysteine synthesis in some bacteria, and this bioconversion has been utilized for cysteine production in industry. We cloned a DNA fragment containing the genes involved in the conversion of L-ATC to L-cysteine from Pseudomonas sp. strain BS. The introduction of this DNA fragment into Escherichia coli cells enabled them to convert L-ATC to cysteine via N-carbamyl-L-cysteine (L-NCC) as an intermediate. The smallest recombinant plasmid, designated pTK10, contained a 2.6-kb insert DNA fragment that has L-cysteine synthetic activity. The nucleotide sequence of the insert DNA revealed that two open reading frames (ORFs) encoding proteins with molecular masses of 19.5 and 44.7 kDa were involved in the L-cysteine synthesis from DL-ATC. These ORFs were designated atcB and atcC, respectively, and their gene products were identified by overproduction of proteins encoded in each ORF and by the maxicell method. The functions of these gene products were examined using extracts of E. coli cells carrying deletion derivatives of pTK10. The results indicate that atcB and atcC are involved in the conversion of L-ATC to L-NCC and the conversion of L-NCC to cysteine, respectively. atcB was first identified as a gene encoding an enzyme that catalyzes thiazolin ring opening. AtcC is highly homologous with L-N-carbamoylases. Since both enzymes can only catalyze the L-specific conversion from L-ATC to L-NCC or L-NCC to L-cysteine, it is thought that atcB and atcC encode L-ATC hydrolase and N-carbamyl-L-cysteine amidohydrolase, respectively.
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PMID:Genes from Pseudomonas sp. strain BS involved in the conversion of L-2-amino-Delta(2)-thiazolin-4-carbonic acid to L-cysteine. 1197 87

Cytidine deaminases are enzymes that catalyze the removal of an amino group from cytidine, forming uridine. APOBEC3 (ApolipoproteinB mRNA editing enzyme, catalytic polypeptide like) proteins are cytidine deaminases that deaminate cytidines in polynucleotides (RNA/DNA), resulting in editing of their target substrates. Mammalian APOBEC3 proteins are an important element in cellular defenses against retrovirus replication, and this "restriction" of retroviral infections is partially due to the cytidine deaminase activity of the APOBEC3. The present protocol (Nair et al., 2014) describes the assay to detect the deaminase activity of mouse APOBEC3 protein, which targets cytidines present in TCC or TTC motifs in a single-stranded DNA substrate. In brief, the protein preparation to be assayed is incubated with a fluorophore-labeled oligodeoxynucleotide containing the deamination target motif (radiolabeled oligonucleotide substrates have also been successfully used by other groups). Cytidines in the oligonucleotide are deaminated to uridines; the addition of Uracil DNA Glycosylase (UDG) catalyzes the hydrolysis of the N-glycosylic bond between uracil and sugar, generating an abasic (AB) site in the oligonucleotide. Mild alkali treatment cleaves the substrate oligonucleotide at the AB site; cleaved products are resolved from uncleaved substrate by denaturing polyacrylamide gel electrophoresis and visualized on a fluorescence scanner. The protocol described here is mainly adapted from that described by Iwatani et al. (2006) with modifications. The assay can, of course, be used to detect the activity of other APOBEC3 deaminases targeting DNA substrates, using oligonucleotides containing the cytidine-containing target sequence for the deaminase.
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PMID:In vitro Assay for Cytidine Deaminase Activity of APOBEC3 Protein. 2750 Jan 86

Hydrazidase was an enzyme that remained unidentified for a half century. However, recently, it was purified, and its encoding gene was cloned. Microbacterium sp. strain HM58-2 grows with acylhydrazides as its sole carbon source; it produces hydrazidase and degrades acylhydrazides to acetate and hydrazides. The bacterial hydrazidase belongs to the amidase signature enzyme family and contains a Ser-cisSer-Lys catalytic motif. The condensation of hydrazine and carbonic acid produces various hydrazides, some of which are raw materials for synthesizing pharmaceuticals and other useful chemicals. Although natural hydrazide compounds have been identified, the metabolic systems for hydrazides are not fully understood. Here, we report the crystal structure of hydrazidase from Microbacterium sp. strain HM58-2. The active site was revealed to consist of a Ser-cisSer-Lys catalytic triad, in which Ser179 forms a covalent bond with a carbonyl carbon of the substrate. 4-Hydroxybenzoic acid hydrazide bound to the S179A mutant, showing an oxyanion hole composed of the three backbone amide groups. Furthermore, H336 in the non-conserved region in the amidase family may define the substrate specificity, which was confirmed by mutation analysis. A wild-type apoenzyme structure revealed an unidentified molecule covalently bound to S179, representing a tetrahedral intermediate.
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PMID:Structural basis of the substrate recognition of hydrazidase isolated from Microbacterium sp. strain HM58-2, which catalyzes acylhydrazide compounds as its sole carbon source. 2790 31