Differences in contacts of RNA polymerases from Escherichia coli and Thermus aquaticus with lacUV5 promoter are determined by core-enzyme of RNA polymerase.
The interaction of RNA polymerases from Escherichia coli and Thermus aquaticus with lacUV5 promoter was studied at various temperatures. Using DNA-protein cross-linking induced by formaldehyde, it was demonstrated that each RNA polymerase formed a unique pattern of contacts with DNA in the open promoter complex. In the case of E. coli RNA polymerase, beta and sigma subunits were involved into formation of cross-links with the promoter, whereas in the case of T. aquaticus RNA polymerase its beta subunit formed the cross-links with the promoter. A cross-linking pattern in promoter complexes of a hybrid holoenzyme comprised of the core-enzyme of E. coli and sigma subunit of T. aquaticus was similar to that of the E. coli holoenzyme. This suggests that DNA-protein contacts in the promoter complex are primarily determined by the core-enzyme of RNA polymerase. However, temperature-dependent behavior of contact formation is determined by the sigma subunit. Results of the present study indicate that the method of formaldehyde cross-linking can be employed for elucidation of differences in the structure of promoter complexes of RNA polymerases from various bacteria.
Kulbachinskiy
A V
AV
Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia. akulb@img.ras.ru
Nikiforov
V G
VG
Brodolin
K L
KL
D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D007763:Lac Operon; D011401:Promoter Regions, Genetic; D013824:Thermus / Q000201:enzymology*
D012321:DNA-Directed RNA Polymerases