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)

An enzyme catalyzing the deamination of the cytosine moiety of blasticidin S was extracted from a fungal strain that belongs to Aspergillus terreus. The enzyme was purified with ammonium sulfate fractionation, Sephadex G-100 column and DEAE cellulose column chromatography, followed by preparative polyacrylamide gel electrophoresis. Blasticidin S deaminase could be separated easily from co-existing cytidine deaminase by DEAE column chromatography or gel electrophoresis, and preliminary study on the substrate specificity showed that this enzyme acts on blasticidin S derivatives, such as cytomycin and acetylblasticidin S, but not on cytosine, cytidine, purine bases or their nucleosides. Blasticidin S deaminase could be induced by the addition of blasticidin S to the culture, and sulfhydryl compounds, such as mercaptoethanol, were effective in protecting the enzyme from inactivation. The homogeneity of the enzyme was examined by both sedimentation analysis and polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were found to be around 30,000 and 4.35, respectively. Some other properties were also examined.
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PMID:Isolation and purification of blasticidin S deaminase from Aspergillus terreus. 23 72

Blasticidin S (BS), a fungicide of microbial origin, is used for the practical control of rice blast disease. It has broad antimicrobial activity but occasionally exhibits adverse phytotoxic effects on some dicot plants. An inactivating enzyme, BS deaminase, was discovered in the BS resistant strain, Bacillus cereus K55-S1, and the structural gene, bsr, for the enzyme has been cloned. We introduced the bsr gene into tobacco plants using the Ti plasmid vector system and demonstrated that the bsr gene conferred a BS resistant phenotype to the plants. Thus the bsr gene could be useful as a selective marker for plant transformation and provides an example for a new approach to the solution of phytotoxicity problems associated with the use of some types of fungicide.
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PMID:Expression of the blasticidin S deaminase gene (bsr) in tobacco: fungicide tolerance and a new selective marker for transgenic plants. 225 Jun 57

Recombinant f1 phages carrying a shuttle vector pKA1M for expression of blasticidin S deaminase were introduced into monkey COS7 cells by mixing with dioctadecylamidoglycylspermine (DOGS). Blasticidin S selection resulted in the detectable growth of resistant colonies within a week. The transfection efficiency depended on the amounts of the phage and DOGS, their ratio, and the time during which the cells were incubated with the phage/DOGS mixture. This method requires only several microliters of an Escherichia coli culture medium containing recombinant f1 phage particles and is applicable to various cell lines including mouse NIH/3T3, chinese hamster CHO-K1, and human HT-1080.
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PMID:Recombinant f1 phage-mediated transfection of mammalian cells using lipopolyamine technique. 769 88

Blasticidin S (BS) deaminase (BSR) from a BS-resistant strain, Bacillus cereus K55-S1, was purified to homogeneity. Molecular weights determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by gel filtration on HPLC are about 15500 and 35000, respectively, indicating the enzyme is a homodimer. The amino acid composition and N-terminal sequence of BSR are the same as those deduced from the nucleotide sequence of the BS-resistant gene, bsr. The optimum temperature and pH for enzyme activity are 60-65 degrees C and near 10.0, respectively. The activity of BSR is inhibited by Cu2+, Hg2+, and p-chloromercuric benzoate (PCMB). Inhibition by PCMB or HgCl2 is reversible by the addition of SH reagents. The enzyme catalyzes the deamination of BS and its derivatives, but not cytosine nucleosides.
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PMID:Inactivation of blasticidin S by Bacillus cereus. V. Purification and characterization of blasticidin S-deaminase mediated by a plasmid from blasticidin S resistant Bacillus cereus K55-S1. 774 11

Blasticidin S deaminase (BSD) is a drug inactivating enzyme produced by Aspergillus terreus, which convert blasticidin S (BS) to a non-toxic deamino-hydroxy derivative. The BSD gene was fused to SV 40 transcriptional regulatory elements and the resulting vector was used to transfect FM3A cells. Expression of BSD conferred resistance to BS and allowed efficient isolation of integrative transfectants which have stably maintained the BS-resistance phenotype after repeated transfer to fresh selective medium. The frequency of transfection was comparable to that with neo and about 80-times greater than with bsr, a BS-resistance gene of bacterial origin which can be used to isolate efficiently transfectant HeLa cells. Using BSD as a selectable marker, we obtained several stable cell lines expressing the firefly luciferase gene. Four independent transfectants among the randomly selected 5 BS-resistance colonies exhibited detectable luciferase activity under the control of dexamethasone-inducible promoter in the expression vector. The successful application of BSD strongly suggests the usefulness of BS as a versatile selective reagent for introduction of cloned DNA sequences into mammalian cells.
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PMID:Blasticidin S deaminase gene from Aspergillus terreus (BSD): a new drug resistance gene for transfection of mammalian cells. 794 22

Blasticidin S deaminase from Aspergillus terreus was crystallized with polyethylene glycol 8000. Two types of crystals were grown under the same crystallization conditions. One type grew as thin plates, while the other had a rhombic shape. The rhombic shaped crystal was suitable for high-resolution crystal structure analysis. Precession photographs and diffraction data showed that the crystal belonged to orthorhombic space group P212121, with unit-cell dimensions a = 70.33, b = 146.56 and c = 56.48 A. The calculated Vm value was acceptable when a tetramer of the enzyme was contained in an asymmetric unit. Preliminary diffraction data were collected to a resolution of 2.0 A with good statistics.
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PMID:Crystallization and preliminary X-ray diffraction studies of blasticidin S deaminase from Aspergillus terreus. 1008 74

Retroviral vectors are commonly used in ex vivo gene therapy protocols. The structure of vectors basically consists of one gene of interest and a selectable marker gene. Fast selection without damaging cells is a critical step for ex vivo gene therapy protocols. Blasticidin S deaminase isolated from Bacillus cereus has a neutralizing action on the highly toxic antibiotic blasticidin S (BS). A commercially available gene coding for blasticidin S deaminase (bsr) when used to construct retroviral vectors, LBSN and LNSB, provided very low levels of BS deaminase activity, precluding their routine use in gene transfer experiments. However, with the introduction of specific mutations into the bsr gene based on the Kozak consensus sequences and deletion of a 5' untranslated sequence to generate bsrm, we were able to construct a retroviral vector encoding resistance to high doses of BS (at least 16-fold above the usual lethal dose in NIH3T3 cells), showing that bsrm/BS may provide a useful system for selection of transduced mammalian cells.
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PMID:Modified blasticidin S resistance gene (bsrm) as a selectable marker for construction of retroviral vectors. 1187 12

Blasticidin S (BS) is an aminoacylnucleoside antibiotic used for the control of rice blast disease. To establish a new cereal transformation system, we constructed a visual marker gene designated gfbsd, encoding an enhanced green fluorescent protein (EGFP) fused to the N-terminus of BS deaminase (BSD). It was cloned into a monocot expression vector and introduced into rice (Oryza sativa L. cv. Nipponbare) calluses by microprojectile bombardment. Three to five weeks after the bombardment, multicellular clusters emitting bright-green EGFP fluorescence were obtained with 10 microg/ml BS, which is not sufficient to completely inhibit the growth of non-transformed tissues. Fluorescent sectors (approximately 2mm in diameter) excised from the calluses regenerated into transgenic plantlets (approximately 10 cm in height) as early as 51 (average 77+/-11) days after the bombardment. The visual antibiotic selection was more efficient and required less time than the bialaphos selection with bar. In addition, the small size (1.1 kb) of gfbsd is preferable for construction of transformation vectors. This new marker gene will make a significant contribution in molecular genetic studies of rice plants.
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PMID:A fluorescent antibiotic resistance marker for rapid production of transgenic rice plants. 1627 91

Blasticidin S is a peptidyl nucleoside antibiotic produced by Streptomyces griseochromogenes that exhibits strong fungicidal activity. To circumvent an effective DNA uptake barrier system in the native producer and investigate its biosynthesis in vivo, the blasticidin S biosynthetic gene cluster (bls) was engrafted to the chromosome of Streptomyces lividans. However, the resulting mutant, LL2, produced the inactive deaminohydroxyblasticidin S instead of blasticidin S. Subsequently, a blasticidin S deaminase (SLBSD, for S. lividans blasticidin S deaminase) was identified in S. lividans and shown to govern this in vivo conversion. Purified SLBSD was found to be capable of transforming blasticidin S to deaminohydroxyblasticidin S in vitro. It also catalyzed deamination of the cytosine moiety of cytosylglucuronic acid, an intermediate in blasticidin S biosynthesis. Disruption of the SLBSD gene in S. lividans LL2 led to successful production of active blasticidin S in the resultant mutant, S. lividans WJ2. To demonstrate the easy manipulation of the blasticidin S biosynthetic gene cluster, blsE, blsF, and blsL, encoding a predicted radical S-adenosylmethionine (SAM) protein, an unknown protein, and a guanidino methyltransferase, were individually inactivated to access their role in blasticidin S biosynthesis.
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PMID:Streptomyces lividans blasticidin S deaminase and its application in engineering a blasticidin S-producing strain for ease of genetic manipulation. 2337 31