Molecular Structure of RNA Polymerase and Its Complex with DNA

The molecular structure of the DNA dependent RNA polymerase [EG 2. 7. 7. 6] from Escherichia coli and the mode of binding of the enzyme to DNA were studied by electron microscopy. The purified enzyme molecules which sedimented at 22S and 15S were negatively stained with phosphotungstic acid. The 22S...

Full description

Saved in:
Bibliographic Details
Published in:Journal of biochemistry (Tokyo) 1969-01, Vol.65 (1), p.1-16
Main Authors: KITANO, YOSHIYUKI, KAMEYAMA, TADANORI
Format: Article
Language:English
Subjects:
DNA, Bacterial
Escherichia coli - enzymology
Freezing
Microscopy, Electron
Models, Structural
Molecular Biology
RNA Nucleotidyltransferases
Ultracentrifugation
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The molecular structure of the DNA dependent RNA polymerase [EG 2. 7. 7. 6] from Escherichia coli and the mode of binding of the enzyme to DNA were studied by electron microscopy. The purified enzyme molecules which sedimented at 22S and 15S were negatively stained with phosphotungstic acid. The 22S RNA polymerase was a cylindrical molecule (diameter, 135± 10 Å: height, 155±15 Å) with an empty core consisted of 22 or 24 oblate spheroids. The structure of the 15S enzyme was uncertain because of instability under the conditions used. On the micrographs of the 22S enzyme taken afrer freezing and thawing only fibrous materials appeared instead of the typical subunit structure. Moreover, the 22S RNA polymerase bound to E. coli DNA was observed by the negative staining technique. The interaction resulted in the conformational alteration of the enzyme.
ISSN:0021-924X
1756-2651
1756-2651
DOI:10.1093/oxfordjournals.jbchem.a128976