scholarly journals Isolation and characterization of the gene encoding an aminopeptidase involved in the selective toxicity of ascamycin toward Xanthomonas campestris pv. citri

1996 ◽  
Vol 319 (1) ◽  
pp. 99-102 ◽  
Author(s):  
Tatsuhiko SUDO ◽  
Kiwako SHINOHARA ◽  
Naoshi DOHMAE ◽  
Koji TAKIO ◽  
Ron USAMI ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Selective Toxicity ◽  
Gene Encoding ◽  
Calculated Molecular Mass ◽  
Isolation And Characterization ◽  
Acid Protein ◽  
Micro Organisms ◽  
Proline Iminopeptidase

An aminopeptidase gene named XAP has been isolated from Xanthomonas campestris pv. citri, a plant pathogenic bacterium. The bacterium is one of the rare micro-organisms susceptible to ascamycin, an aminoacyl nucleoside antibiotic that inhibits protein synthesis. Sequence analysis reveals that the gene encodes a 311 amino acid protein with a calculated molecular mass of 35134 Da and approx. 50% identity for amino acids to the proline iminopeptidase from Neisseria gonorrhoeae. The XAP gene product, Xap, expressed in Escherichia coli has proline iminopeptidase activity as well as ascamycin dealanylating activity in vitro.

Isolation and characterization of temperature-sensitive mutations in RPA190, the gene encoding the largest subunit of RNA polymerase I from Saccharomyces cerevisiae

1988 ◽  
Vol 8 (10) ◽  
pp. 3997-4008
Author(s):  
M Wittekind ◽  
J Dodd ◽  
L Vu ◽  
J M Kolb ◽  
J M Buhler ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase I ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Mutant Strains ◽  
Polymerase I

The isolation and characterization of temperature-sensitive mutations in RNA polymerase I from Saccharomyces cerevisiae are described. A plasmid carrying RPA190, the gene encoding the largest subunit of the enzyme, was subjected to in vitro mutagenesis with hydroxylamine. Using a plasmid shuffle screening system, five different plasmids were isolated which conferred a temperature-sensitive phenotype in haploid yeast strains carrying the disrupted chromosomal RPA190 gene. These temperature-sensitive alleles were transferred to the chromosomal RPA190 locus for mapping and physiology experiments. Accumulation of RNA was found to be defective in all mutant strains at the nonpermissive temperature. In addition, analysis of pulse-labeled RNA from two mutant strains at 37 degrees C showed that the transcription of rRNA genes was decreased, while that of 5S RNA was relatively unaffected. RNA polymerase I was partially purified from several of the mutant strains grown at the nonpermissive temperature and was shown to be deficient when assayed in vitro. Fine-structure mapping and sequencing of the mutant alleles demonstrated that all five mutations were unique. The rpa190-1 and rpa190-5 mutations are tightly clustered in region I (S.S. Broyles and B. Moss, Proc. Natl. Acad. Sci. USA 83:3141-3145, 1986), the putative zinc-binding region that is common to all eucaryotic RNA polymerase large subunits. The rpa190-3 mutation is located between regions III and IV, and a strain carrying it behaves as a mutant that is defective in the synthesis of the enzyme. This mutation lies within a previously unidentified segment of highly conserved amino acid sequence homology that is shared among the largest subunits of eucaryotic nuclear RNA polymerases. Another temperature-sensitive mutation, rpa190-2, creates a UGA nonsense codon.

scholarly journals Isolation and characterization of temperature-sensitive mutations in RPA190, the gene encoding the largest subunit of RNA polymerase I from Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (10) ◽  
pp. 3997-4008 ◽  
Author(s):  
M Wittekind ◽  
J Dodd ◽  
L Vu ◽  
J M Kolb ◽  
J M Buhler ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase I ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Mutant Strains ◽  
Polymerase I

The isolation and characterization of temperature-sensitive mutations in RNA polymerase I from Saccharomyces cerevisiae are described. A plasmid carrying RPA190, the gene encoding the largest subunit of the enzyme, was subjected to in vitro mutagenesis with hydroxylamine. Using a plasmid shuffle screening system, five different plasmids were isolated which conferred a temperature-sensitive phenotype in haploid yeast strains carrying the disrupted chromosomal RPA190 gene. These temperature-sensitive alleles were transferred to the chromosomal RPA190 locus for mapping and physiology experiments. Accumulation of RNA was found to be defective in all mutant strains at the nonpermissive temperature. In addition, analysis of pulse-labeled RNA from two mutant strains at 37 degrees C showed that the transcription of rRNA genes was decreased, while that of 5S RNA was relatively unaffected. RNA polymerase I was partially purified from several of the mutant strains grown at the nonpermissive temperature and was shown to be deficient when assayed in vitro. Fine-structure mapping and sequencing of the mutant alleles demonstrated that all five mutations were unique. The rpa190-1 and rpa190-5 mutations are tightly clustered in region I (S.S. Broyles and B. Moss, Proc. Natl. Acad. Sci. USA 83:3141-3145, 1986), the putative zinc-binding region that is common to all eucaryotic RNA polymerase large subunits. The rpa190-3 mutation is located between regions III and IV, and a strain carrying it behaves as a mutant that is defective in the synthesis of the enzyme. This mutation lies within a previously unidentified segment of highly conserved amino acid sequence homology that is shared among the largest subunits of eucaryotic nuclear RNA polymerases. Another temperature-sensitive mutation, rpa190-2, creates a UGA nonsense codon.

PENGEMBANGAN TEKNOLOGI SELEKSI IN VITRO BERULANG (REPEAT CYCLING–IN VITRO SELECTION) TOLERAN STRES KEKERINGAN UNTUK PERBAIKAN MUTU GENETIK DAN PRODUKSI TANAMAN KEDELAI BERMIKORIZA

2017 ◽  
Vol 1 (1) ◽  
pp. 74-84
Author(s):  
Ahmad Riduan ◽  
Rainiyati Rainiyati ◽  
Yulia Alia
Keyword(s):  
Arbuscular Mycorrhizae ◽  
In Vitro Selection ◽  
Soil Samples ◽  
Single Spore ◽  
Isolation And Characterization ◽  
Single Spore Culture ◽  
Spore Culture ◽  
Glomus Sp

Every plant rhizospheres in any ecosystem there are various living microorganisms including Arbuscular Mycorrhizae Fungi (AMF).  An isolation and characterization is required to investigate the species or type of the AMF. This research was aimed at studying the isolation and characterization of AMF sporulation in soybean rhizospheres in Jambi Province. The results of evaluation on soil samples before trapping showed that there are spores from three genus of AMF twelve types Glomus , two types Acaulospora and one type of Enthrophospora.  Following single spore culture in soybean rhizosphere, 5 spore types were obtained:  Glomus sp-1, Glomus sp-4, Glomus sp-7, Glomus sp-8 Glomus sp-10.

Isolation and characterization of a bovine gene encoding phenol sulfotransferase

Gene ◽  
1996 ◽  
Vol 174 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Travis Henry ◽  
Brian Kliewer ◽  
Robert Palmatier ◽  
Joseph S. Ulphani ◽  
Joe D. Beckmann
Keyword(s):  
Gene Encoding ◽  
Bovine Gene ◽  
Isolation And Characterization ◽  
Phenol Sulfotransferase

Arginine synthesis by hepatomas in vitro. II. Isolation and characterization of Morris hepatoma variants unable to convert ornithine to arginine, and modulation of urea-cycle enzymes by dexamethasone and cyclic-AMP

1984 ◽  
Vol 68 (1) ◽  
pp. 305-319
Author(s):  
S.J. Goss
Keyword(s):  
Cyclic Amp ◽  
Liver Cells ◽  
Isolation And Characterization ◽  
Rat Liver Cells ◽  
Morris Hepatoma ◽  
Ornithine Transcarbamoylase ◽  
Cellular Incorporation

‘77orn’, a derivative of the Morris rat hepatoma 7777, stably expresses high levels of ornithine transcarbamoylase (OTC) and carbamoylphosphate synthetase I (CPS-I), and is able to grow indefinitely in ornithine-medium (medium with ornithine in place of arginine). Variants that have lost this ability are isolated from 77orn by a ‘suicide’ selective technique dependent on the cellular incorporation of [3H]ornithine. These variants, which have reduced levels of CPS-I, or of both CPS-I and OTC, are shown to have developed multiple hormonal requirements; their enzyme deficiencies can be reversed by use of an appropriately supplemented medium. In particular, CPS-I is inducible by dexamethasone and dibutyryl-cyclic-AMP in combination. Cholera toxin can be used instead of cyclic-AMP, but then butyrate is additionally required if the induction is to be maintained in the long term. The use of these agents in excess can depress OTC. Several other hepatomas, and alos explanted foetal rat liver cells, have similar requirements for CPS-I expression. It is argued that multiple hormonal requirements for CPS-I production are normal in liver cells in vitro, and that hormone-independent hepatomas should be regarded as abnormal. The implications of this for the somatic cell genetic investigation of differentiation are briefly discussed.

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