Identification of a mutation within the structural gene for the a subunit of DNA-dependent RNA polymerase of E. coli

1976 ◽  
Vol 145 (1) ◽  
pp. 19-22 ◽  
Author(s):  
H. Fujiki ◽  
P. Palm ◽  
W. Zillig ◽  
R. Calendar ◽  
M. Sunshine
Keyword(s):  
Rna Polymerase ◽  
Structural Gene ◽  
E Coli ◽  
A Subunit

Vibrio harveyi RNA polymerase: purification and resolution from gyrase A

1992 ◽  
Vol 70 (8) ◽  
pp. 698-702 ◽  
Author(s):  
Elana Swartzman ◽  
Edward A. Meighen
Keyword(s):  
Rna Polymerase ◽  
Topoisomerase Ii ◽  
Vibrio Harveyi ◽  
In Vitro Transcription ◽  
E Coli ◽  
Gyrase A ◽  
A Subunit ◽  
Terminal Amino ◽  
Promoter Specificity

RNA polymerase was purified from Vibrio harveyi and found to contain polypeptides (β,β′, α, and σ) closely corresponding to those of the Escherichia coli enzyme. In vitro transcription studies using V. harveyi and E. coli RNA polymerase demonstrated that the purified V. harveyi RNA polymerase is functional and that the two enzymes have the same promoter specificity. Chromatography through a monoQ column was required to remove a 100-kilodalton protein that was present in large amounts and copurified with the RNA polymerase. N-terminal amino acid sequencing showed that the first 18 amino acids of the 100-kilodalton protein shares 78% sequence identity with the A subunit of gyrase or topoisomerase II. The abundance of the gyrase A protein is unprecedented and may be linked to bioluminescence.Key words: Vibrio harveyi, RNA polymerase, gyrase, bioluminescence.

scholarly journals Escherichia coli mutations that prevent the action of the T4 unf/alc protein map in an RNA polymerase gene.

Genetics ◽  
1988 ◽  
Vol 118 (2) ◽  
pp. 173-180
Author(s):  
L Snyder ◽  
L Jorissen
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Bacteriophage T4 ◽  
Strong Support ◽  
Rpob Gene ◽  
Late Gene Expression ◽  
Gene Encoding ◽  
E Coli ◽  
A Subunit ◽  
Phage Production

Abstract Bacteriophage T4 has the substituted base hydroxymethylcytosine in its DNA and presumably shuts off host transcription by specifically blocking transcription of cytosine-containing DNA. When T4 incorporates cytosine into its own DNA, the shutoff mechanism is directed back at T4, blocking its late gene expression and phage production. Mutations which permit T4 multiplication with cytosine DNA should be in genes required for host shutoff. The only such mutations characterized thus far have been in the phage unf/alc gene. The product of this gene is also required for the unfolding of the host nucleoid after infection, hence its dual name unf/alc. As part of our investigation of the mechanism of action of unf/alc, we have isolated Escherichia coli mutants which propagate cytosine T4 even if the phage are genotypically alc+. These same E. coli mutants are delayed in the T4-induced unfolding of their nucleoid, lending strong support to the conclusion that blocking transcription and unfolding the host nucleoid are but different manifestations of the same activity. We have mapped two of the mutations, called paf mutations for prevent alc function. They both map at about 90 min, probably in the rpoB gene encoding a subunit of RNA polymerase. From the behavior of Paf mutants, we hypothesize that the unf/alc gene product of T4 interacts somehow with the host RNA polymerase to block transcription of cytosine DNA and unfold the host nucleoid.

scholarly journals Identification of a mutation within the structural gene for the α subunit of DNA-dependent RNA polymerase of E. Coli

1976 ◽  
Vol 147 (1) ◽  
pp. 119-119
Author(s):  
H. Fujiki ◽  
P. Palm ◽  
W. Zillig ◽  
R. Calendar ◽  
M. Sunshine
Keyword(s):  
Rna Polymerase ◽  
Structural Gene ◽  
Α Subunit ◽  
E Coli

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Inactivation of E. coli RNA polymerase by polyriboinosinic acid: Heterogeneity of RS complexes

1979 ◽  
Vol 173 (1) ◽  
pp. 51-59 ◽  
Author(s):  
William J. DeLorbe ◽  
Stefan Surzycki ◽  
Gary Gussin
Keyword(s):  
Rna Polymerase ◽  
E Coli

scholarly journals A NEW MAP LOCATION FOR THE ilvB LOCUS OF ESCHERICHIA COLI

Genetics ◽  
1980 ◽  
Vol 96 (1) ◽  
pp. 59-77
Author(s):  
Thomas C Newman ◽  
Mark Levinthal
Keyword(s):  
Escherichia Coli ◽  
Structural Gene ◽  
Acetolactate Synthase ◽  
Deletion Mapping ◽  
Donor Strain ◽  
E Coli ◽  
Linkage Of Genes ◽  
Map Location ◽  
New Alleles

ABSTRACT We isolated, in E. coli K12, new alleles of the ilvB locus, the structural gene for acetolactate synthase isoenzyme I, and showed them to map at or near the ilvB619 site. The map position of the ilvB locus was redetermined because plasmids containing the ilvC-cya portion of the chromosome did not complement mutations at the ilvB locus. Furthermore, diploids for the ilvEDAC genes formed with these plasmids in an ilvHI background facilitated the isolation of the new ilvB alleles. The ilvB locus was remapped and found to be located at 81.5 minutes, between the uhp and dnaA loci. This location was determined by two- and three-point transductional crosses, deletion mapping and complementation with newly isolated plasmids. One of the new alleles of the ilvB gene is a mu-1 insertion. When present in the donor strain, this allele interferes with the linkage of genes flanking the mu-1 insertion, as well as the linkage of genes to either side of the mu-1 insertion.

scholarly journals A genetically detoxified derivative of heat-labile Escherichia coli enterotoxin induces neutralizing antibodies against the A subunit.

1994 ◽  
Vol 180 (6) ◽  
pp. 2147-2153 ◽  
Author(s):  
M Pizza ◽  
M R Fontana ◽  
M M Giuliani ◽  
M Domenighini ◽  
C Magagnoli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
Neutralizing Antibodies ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
E Coli ◽  
Heat Labile ◽  
A Subunit ◽  
Adp Ribosyltransferase ◽  
Derivatives Of

Escherichia coli enterotoxin (LT) and the homologous cholera toxin (CT) are A-B toxins that cause travelers' diarrhea and cholera, respectively. So far, experimental live and killed vaccines against these diseases have been developed using only the nontoxic B portion of these toxins. The enzymatically active A subunit has not been used because it is responsible for the toxicity and it is reported to induce a negligible titer of toxin neutralizing antibodies. We used site-directed mutagenesis to inactivate the ADP-ribosyltransferase activity of the A subunit and obtained nontoxic derivatives of LT that elicited a good titer of neutralizing antibodies recognizing the A subunit. These LT mutants and equivalent mutants of CT may be used to improve live and killed vaccines against cholera and enterotoxinogenic E. coli.

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