SUNY at Albany
June 19-23, 2001
Structural studies of prokaryotic RNA polymerases
The 3.3 ?-resolution X-ray crystal structure of Thermus aquaticus core RNA polymerase (1) provides a basis for further structural and functional studies. The path of the transcript RNA and template DNA through the RNA polymerase structure was tracked using RNA-protein and DNA-protein crosslinks, resulting in a model of the ternary elongation complex (2). A co-crystal structure of core RNA polymerase complexed with rifampicin reveals the structural mechanism of the antibioticsÕ inhibition mechanism (3). Work currently in progress includes analysis of additional inhibitor complexes, analysis conformational flexibility in the RNA polymerase molecule by comparison of different crystal forms, and high-resolution X-ray structures of promoter-specificity s factor domains comprising most of Thermus aquaticus sA. Finally, the structure of an open promoter complex of Thermus aquaticus holoenzyme with promoter DNA, obtained by fitting the high-resolution structures of core RNA polymerase, s factor domains, and DNA into a 6.5 ?-resolution X-ray map, will be described.References and Footnotes
Elizabeth A. Campbell, Shoko Masuda, Katsuhiko Murakami, Natacha Opalka, and Seth A. Darst
The Rockefeller University, New York, NY 10021, USA.