scholarly journals The Template Specificity of Bacteriophage  6 RNA Polymerase

2013 ◽  
Vol 87 (18) ◽  
pp. 10190-10194 ◽  
Author(s):  
J. Qiao ◽  
L. Mindich
Nature ◽  
1969 ◽  
Vol 224 (5214) ◽  
pp. 35-37 ◽  
Author(s):  
RICHARD LOSICK ◽  
ABRAHAM L. SONENSHEIN

Nature ◽  
1969 ◽  
Vol 223 (5211) ◽  
pp. 1111-1113 ◽  
Author(s):  
WILLIAM C. SUMMERS ◽  
RUTH B. SIEGEL

1974 ◽  
Vol 52 (11) ◽  
pp. 966-973 ◽  
Author(s):  
H. Nishimoto ◽  
I. Takahashi

In order to investigate relations between template specificity of RNA polymerase and sporulation, RNA polymerase activities in partially purified preparations from various asporogenous mutants were measured with poly[d(A-T)] or DNA from phage PBS 15 as template. Results obtained suggest that morphological changes occurring during sporulation may not be tightly linked temporally to transcriptional events.Subunits of RNA polymerase from these mutants were analyzed by sodium dodecyl sulfate – polyacrylamide gel electrophoresis after purification by (NH4)2SO4 precipitation, DEAE-cellulose chromatography, phosphocellulose chromatography, and glycerol gradient centrifugation. Phenylmethylsulfonyl fluoride was present throughout the purification procedure to prevent proteolytic degradation. It was found that β and β′ subunits were present in 1:1 ratio in all preparations. In addition to β, β′, and α subunits, a protein having a molecular weight of 95 000 was found in enzyme preparations from a wild-type strain and stage II mutants harvested at t5–t9. This protein was absent in stage 0 mutants and in all strains harvested in log phase. The enzyme containing this protein was eluted from phosphocellulose column with 0.6 M KCl rather than 0.35 M KCl, which eluted the enzyme without the 95 000 dalton protein. Furthermore the enzyme with this protein showed a sedimentation coefficient higher than that of the enzyme without the 95 000 dalton protein.


2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Addie Smith ◽  
Bradley Bursavich ◽  
Jeffrey Temple ◽  
Michael Doughty

1972 ◽  
Vol 127 (1) ◽  
pp. 69-80 ◽  
Author(s):  
B. Gregory Louis ◽  
P. S. Fitt

1. The subunits α and β of Halobacterium cutirubrum DNA-dependent RNA polymerase have been purified to electrophoretic homogeneity. Both have mol.wt. 18000 and they are required in equimolar amounts for optimum activity. 2. The instability of the complete enzyme, αβ, in the absence of salt is due to the rapid inactivation of the β subunit in these conditions. 3. Nearest-neighbour analysis of the product formed on poly[d(A-T)] as template shows that the enzyme copies the latter accurately. 4. The enzyme initiates new chains with purine nucleoside triphosphates exclusively. 5. The product obtained in the standard assay conditions contains some high mol.wt. (>16S) material, but consists primarily of short chains, of average length 70–80 nucleotide units. 6. The template specificity of the complete enzyme has been studied at high and low ionic strength. Its extreme dependence on salt concentration is unrelated to the gross overall base composition of the DNA used. 7. T7 DNA is transcribed asymmetrically and the enzyme selectively copies the T7 `early' genes. 8. Preliminary amino acid analyses of α and β subunits show that their overall content of acidic, basic and neutral amino acids does not differ appreciably from that of Escherichia coli RNA polymerase.


Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi

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.


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