Quinol binding sites and ubisemiquinone stabilisation in the Escherichia coli quinol oxidase, cytochrome bo3. A discussion of models for structure and function

1999 ◽  
Vol 27 (3) ◽  
pp. A81-A81
Author(s):  
W. John Ingledew ◽  
Lewis Murray ◽  
Ricardo H. Pires
1970 ◽  
Vol 117 (3) ◽  
pp. 623-631 ◽  
Author(s):  
Volker Neuhoff ◽  
Wolf-Bernhard Schill ◽  
Hans Sternbach

By using micro disc electrophoresis and micro-diffusion techniques, the interaction of pure DNA-dependent RNA polymerase (EC 2.7.7.6) from Escherichia coli with the template, the substrates and the inhibitors heparin and rifampicin was investigated. The following findings were obtained: (1) heparin converts the 24S and 18S particles of the polymerase into the 13S form; (2) heparin inhibits RNA synthesis by dissociating the enzyme–template complex; (3) rifampicin does not affect the attachment of heparin to the enzyme; (4) the substrates ATP and UTP are bound by enzyme loaded with rifampicin; (5) rifampicin is bound by an enzyme–template complex to the same extent as by an RNA-synthesizing enzyme–template complex. From this it is concluded that the mechanism of the inhibition of RNA synthesis by rifampicin is radically different from that by heparin. As a working hypothesis to explain the inhibitory mechanism of rifampicin, it is assumed that it becomes very firmly attached to a position close to the synthesizing site and only blocks this when no synthesis is in progress.


2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.


1993 ◽  
Vol 268 (36) ◽  
pp. 27094-27099
Author(s):  
B Stolz ◽  
M Huber ◽  
Z Marković-Housley ◽  
B Erni

2007 ◽  
Vol 1 (1) ◽  
pp. 89-91 ◽  
Author(s):  
Julien Boudet ◽  
Anne Chouquet ◽  
Aicha Chahboune ◽  
Cécile Giustini ◽  
Bernard Joris ◽  
...  

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