共查询到20条相似文献,搜索用时 46 毫秒
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Promoter architecture in the flagellar regulon of Bacillus subtilis: high-level expression of flagellin by the sigma D RNA polymerase requires an upstream promoter element. 总被引:5,自引:1,他引:5 下载免费PDF全文
K Fredrick T Caramori Y F Chen A Galizzi J D Helmann 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(7):2582-2586
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An Immunological Assay for the Sigma Subunit of RNA Polymerase in Extracts of Vegetative and Sporulating Bacillus subtilis 总被引:16,自引:2,他引:14 下载免费PDF全文
Robert Tjian Richard Losick 《Proceedings of the National Academy of Sciences of the United States of America》1974,71(7):2872-2876
The activity of the sigma subunit of Bacillus subtilis RNA polymerase decreases markedly during the first hours of sporulation [T.G. Linn et al. (1973) Proc. Nat. Acad. Sci. USA 70, 1865-1869]. We have prepared antibody against RNA polymerase holoenzyme to determine the fate of sigma polypeptide during spore formation. This antiserum specifically and independently precipitates sigma and core polymerase from crude extracts of B. subtilis as judged by both sodium dodecyl sulfate and urea gel electrophoresis of the precipitates. We report that crude extracts of sporulating cells lacking sigma activity contain as much sigma polypeptide as extracts of vegetative cells. However, sigma polypeptide in extracts from sporulating cells is apparently only weakly associated with RNA polymerase, as indicated by the failure of sigma to co-purify efficiently with core enzyme during phase partitioning.The loss of sigma activity and the weak binding of sigma to core enzyme occurs normally in a mutant blocked at an intermediate stage of sporulation (SpoII-4Z) and in wild-type bacteria sporulating in 121B medium, Difco sporulation medium, or Sterlini-Mandelstam resuspension medium. In contrast, sigma in two mutants (SpoOa-5NA and SpoOb-6Z) blocked at an early stage of spore formation remains active and tightly associated with RNA polymerase during stationary phase. 相似文献
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Caroline Hussey Janice Pero Rosalind G. Shorenstein Richard Losick 《Proceedings of the National Academy of Sciences of the United States of America》1972,69(2):407-411
Two kinds of hybridization competition experiments show that Bacillus subtilis RNA polymerase synthesizes ribosomal RNA (rRNA) in vitro with B. subtilis DNA as a template. First, RNA synthesized in vitro competes with the hybridization of [(32)P]rRNA synthesized in vivo to the heavy strand of B. subtilis DNA. Second, unlabeled rRNA synthesized in vivo competes with the hybridization of [(3)H]RNA synthesized in vitro to denatured DNA or heavy-strand DNA, but not to light-strand DNA. The ability of RNA polymerase holoenzyme to synthesize rRNA in vitro is not lost after extensive purification. RNA polymerase core enzyme, however, which is missing the sigma factor, synthesizes little rRNA in vitro.RNA polymerase purified from wild-type sporulating cells synthesizes little rRNA in vitro, while the in vitro synthesis of rRNA by RNA polymerase from stationary phase cells of the sporulation-defective mutant rfr 10 is apparently unimpaired. 相似文献
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DNA sequence analysis suggests that expression of flagellar and chemotaxis genes in Escherichia coli and Salmonella typhimurium is controlled by an alternative sigma factor. 总被引:48,自引:6,他引:48 下载免费PDF全文
J D Helmann M J Chamberlin 《Proceedings of the National Academy of Sciences of the United States of America》1987,84(18):6422-6424
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Analysis of the Streptomyces coelicolor sigE gene reveals the existence of a subfamily of eubacterial RNA polymerase sigma factors involved in the regulation of extracytoplasmic functions. 总被引:18,自引:1,他引:17 下载免费PDF全文
M A Lonetto K L Brown K E Rudd M J Buttner 《Proceedings of the National Academy of Sciences of the United States of America》1994,91(16):7573-7577
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Spo0A binds to a promoter used by sigma A RNA polymerase during sporulation in Bacillus subtilis. 总被引:23,自引:1,他引:23 下载免费PDF全文
S Satola P A Kirchman C P Moran Jr 《Proceedings of the National Academy of Sciences of the United States of America》1991,88(10):4533-4537
Examination of the effects of 56 single-base-pair substitutions in the spoIIG promoter and studies of the interaction of the spo0A product (Spo0A) with this promoter in vitro demonstrated that Spo0A acts directly to enable this promoter to be used by sigma A-associated RNA polymerase (EC 2.7.7.6). The spoIIG operon from Bacillus subtilis is transcribed during sporulation by a form o RNA polymerase containing sigma A, the primary sigma factor in vegetative cells. The spoIIG promoter is unusual in that it contains sequences that are similar to those found at the -10 and -35 regions of promoters that are used by sigma A-associated RNA polymerase, but these sigma A-like recognition sequences are separated by 22 base pairs rather than the typical 17 or 18 base pairs. We found that single-base-pair substitutions in the around the -35-like sequence, and substitutions in a region upstream from this position, around position -87, reduced promoter activity. DNase I protection and electrophoretic gel mobility shift assays were used to demonstrate that Spo0A binds specifically to these regions in vitro. Evidently, the -35-like sequence is part of a Spo0A binding site and therefore is possibly not a sigma A-recognition sequence. These results support a model in which Spo0A activates the spoIIG promoter after the onset of endospore formation. 相似文献
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Two alkaline phosphatase genes positioned in tandem in Bacillus licheniformis MC14 require different RNA polymerase holoenzymes for transcription. 总被引:3,自引:0,他引:3 下载免费PDF全文
F M Hulett P Z Wang M Sussman J W Lee 《Proceedings of the National Academy of Sciences of the United States of America》1985,82(4):1035-1039