Isolation and characterization of immunity temperature sensitive mutants of Enterobacter cloacae harbouring the cloacinogenic factor DF13

1972 ◽  
Vol 114 (4) ◽  
pp. 312-324 ◽  
Author(s):  
A. J. Kool ◽  
H. J. J. Nijkamp
Keyword(s):  
Enterobacter Cloacae ◽  
Temperature Sensitive ◽  
Temperature Sensitive Mutants ◽  
Isolation And Characterization

Genetic and biochemical studies of asparagine-linked oligosaccharide assembly

1982 ◽  
Vol 300 (1099) ◽  
pp. 207-223 ◽  
Keyword(s):  
Protein Synthesis ◽  
Temperature Sensitive ◽  
Temperature Sensitive Mutants ◽  
Isolation And Characterization ◽  
Oligosaccharide Processing ◽  
Biochemical Studies ◽  
The Common ◽  
Specific Lipid ◽  
Temperature Sensitive Phenotype

The formation of N -glycosidic linkages of eukaryotic glycoproteins involves the assembly of a specific lipid-linked precursor oligosaccharide in the endoplasmic reticulum. This oligosaccharide is transferred from the lipid carrier to appropriate asparagine residues during protein synthesis. The protein-linked oligosaccharide then undergoes processing reactions that include both removal and addition of carbohydrate residues. In this paper we report recent studies from our laboratory on the synthesis of asparagine-linked oligosaccharides. In the first part we describe the isolation and characterization of temperature-sensitive mutants of yeast blocked at specific stages in the assembly of the lipid-linked oligosaccharide. In addition, we are using these mutants to clone the genes for the enzymes in this pathway by complementation of the temperature-sensitive phenotype. The second part deals with the topography of asparagine-linked oligosaccharide assembly. Our studies on the transmembrane movement of sugar residues during the assembly of secreted glycoproteins from cytoplasmic precursors are presented. Finally, experiments on the control of protein-linked oligosaccharide processing are described. Recent data are presented on the problem of how specific oligosaccharides are assembled from the common precursors at individual sites on glycoproteins.

Isolation and characterization of temperature-sensitive mutants of echovirus 12

Virology ◽  
1979 ◽  
Vol 99 (2) ◽  
pp. 329-339 ◽  
Author(s):  
Thomas Adrian ◽  
Brigitte Rosenwirth ◽  
Hans J. Eggers
Keyword(s):  
Temperature Sensitive ◽  
Temperature Sensitive Mutants ◽  
Isolation And Characterization

Isolation and Characterization of Temperature-Sensitive Mutants of Venezuelan Encephalitis Virus

Virology ◽  
1981 ◽  
Vol 110 (1) ◽  
pp. 197-201 ◽  
Author(s):  
Bette A. Pancake ◽  
Zsolt P. Harsanyi ◽  
Michael E. Wiebe ◽  
Emilio A. Emini ◽  
William F. Scherer
Keyword(s):  
Encephalitis Virus ◽  
Temperature Sensitive ◽  
Temperature Sensitive Mutants ◽  
Isolation And Characterization

scholarly journals ISOLATION AND CHARACTERIZATION OF dnaX AND dnaY TEMPERATURE-SENSITIVE MUTANTS OF ESCHERICHIA COLI

Genetics ◽  
1979 ◽  
Vol 92 (4) ◽  
pp. 1041-1059
Author(s):  
Joan M Henson ◽  
Herman Chu ◽  
Carleen A Irwin ◽  
James R Walker
Keyword(s):  
Escherichia Coli ◽  
Dna Synthesis ◽  
Fold Increase ◽  
Temperature Sensitive ◽  
E Coli ◽  
Temperature Sensitive Mutants ◽  
Isolation And Characterization ◽  
Ts Mutations

ABSTRACT Escherichia coli mutants with temperature-sensitive (ts) mutations in dnaX and dnaY genes have been isolated. Based on transduction by phage PI, dnaX and Y have been mapped at minutes 10.4-10.5 and 12.1, respectively, in the sequence dnaX purE dnaY. Both dnaXts36 and YtslO are recessive to wild-type alleles present on episomes. F13 carries both dnaX  + and Y  +; the shorter F210 carries dnaY  +, but not X  +. Lambda transducing phages that carry dnaX  + or Y  + have been isolated, and hybrid plasmids of Col E1 and E. coli DNA from the CLARKE and CARBON (1976) collection also carry portions of the dnaX purE dnaY region. Results obtained with the λ transducing phages and the hybrid plasmids suggest that dnaX is a different gene from the previously characterized dnaZ gene, which is also near minute 10.5.—The dnaXts36 mutant, after a shift to 42°, stopped DNA synthesis gradually, and the total amount of DNA increased two-fold. When this mutant was shifted to M°, the rate of DNA synthesis dropped immediately and the final increment of DNA was only 10% of the initial amount. Replicative DNA synthesis in toluene-treated cells was completely inhibited at 42° and was partially in-hibited even at 30°.—When the dnaYtslO mutant was shifted to 42°, DNA synthesis gradually stopped, and the amount of DNA increased 3.6-fold. At 44°, residual DNA synthesis amounted to a two-fold increase. Replicative DNA synthesis in vitro in toluene-treated cells was inactivated after 20 minutes at 42° or by "preincubation" of cells at 42° before toluene treatment.— The dnaX and dnaY products probably function in polymerization of DNA, although participation also in initiation cannot be excluded.

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