Conformational changes of Escherichia coli sigma54-RNA-polymerase upon closed-promoter complex formation.
RNA polymerase from the mesophile Escherichia coli exists in two forms, the core enzyme and the holoenzyme. Using cryo-electron microscopy and single-particle analysis, we have obtained the structure of the complete RNA polymerase from E.coli containing the sigma54 factor within the closed-promoter complex. Comparisons with earlier reconstructions of the core enzyme and the sigma54 holoenzyme reveal the behaviour of this major variant RNA polymerase in defined functional states. The binding of DNA leads to significant conformational changes in the enzyme's catalytic subunits, apparently a necessity for the initiation of enhancer-dependent promoter-specific transcription.
Ray
Pampa
P
Department of Biological Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Hall
Richard J
RJ
Finn
Robert D
RD
Chen
Shaoxia
S
Patwardhan
Ardan
A
Buck
Martin
M
van Heel
Marin
M
D001665:Binding Sites; D020285:Cryoelectron Microscopy; D003460:Crystallization; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D004926:Escherichia coli / Q000201:enzymology*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011487:Protein Conformation; D051877:RNA Polymerase Sigma 54 / Q000737:chemistry* / Q000648:ultrastructure; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D051877:RNA Polymerase Sigma 54