Novel RNA polymerase sigma factor from Bacillus subtilis.

Abstract

A modified form of Bacillus subtifis RNA polymerase (RNA nucleotidyltransferase) has been isolated that exhibits distinctive transcriptional specificity. This modified enzyme transcribes two cloned genes from the purA-cysA region of the B. subtilis chromosome whose expression in vivo is associated with the process of sporulation. Neither of these genes is transcribed by tie usual form of B. subtilis RNA polymerase holoenzyme containing a a factor of 55,000 daltons (I4 The modified RNA polymerase lacks -55 but contains a newly identified subunit of 37,000 daltons termed oP7. A reconstitution experiment in which (P was added to core RNA polymerase strongly suggests that (37 is responsible for the transcriptional specificity of the modified RNA polymerase. (37 apparently acts at the level of promoter recognition; this transcriptional determinant enabled core RNA polymerase to form stable binary and ternary ("initiation") complexes with endonuclease restriction fragments containing promoters for the cloned B. subtilis genes. The first step in transcription of genes in bacteria is the formation of a binary complex of RNA polymerase (RNA nucleotidyltransferase) with promoter sites on DNA (1). The recognition of promoters is catalyzed by a subunit of RNA polymerase known as a. This polypeptide confers on the core component (f'(3a2) of the bacterial transcriptase the ability to bind at and initiate RNA synthesis from specific sites on the DNA template. The discovery that a factor governs site selection in bacteria prompted the proposal that different species of a polypeptide could recognize different classes of promoters (2). Indeed, certain bacteriophage are now known to encode a-like proteins that direct the transcription of phage genes. In Bacillus subtilis phage SPO1 (and its close relative SP82), phage-coded a-like factors replace the host a factor on the B. subtilis transcriptase, thereby converting the bacterial RNA polymerase to a form that recognizes phage "middle" (3-6) and "late" gene promoters (7,8). The promoters for phage "middle" genes have distinctive nucleotide sequences that differ strikingly from the promoters controlled by the host a factor (9).Until now multiple species of a factor in uninfected bacteria have not been described. Recently, however, we (10) isolated a modified form of B. subtilis RNA polymerase that transcribes two cloned B. subtilis genes whose transcription in vivo is associated with the process of sporulation (11-13). Neither of these genes is transcribed by the usual form of B. subtilis RNA polymerase holoenzyme (14, 15) containing a a factor of 55,000 daltons (a55). The modified RNA polymerase lacks a'5 but contains a newly identified subunit of 37,000 daltons. Here we show by means of a reconstitution experiment that the 37,000-dalton polypeptide (herein termed o37) is a a-like factor that confers novel promoter recognition properties on core RNA polymerase. Thus, B. subtilis core RNA polymerase interacts with a variety of bacterial and phage-coded a factors to acquire ...

Extended Sequence and Functional Analysis of the Butirosin Biosynthetic Gene Cluster in Bacillus circulans SANK 72073

“…Therefore, orf1 appears to be in a different operon. It should be pointed out then that a consensus promoter sequence was found in the upstream of btrR1 (Figure 1) [23]. Thus, an operon starting the btrR1 gene was envisioned to be the butirosin biosynthetic gene cluster.…”

Alternative transcription factor sigmaSB of Staphylococcus aureus: characterization and role in transcription of the global regulatory locus sar

“…Our in vitro studies revealed that transcription from the P1 promoter is dependent on the primary factor SA , while that of the P3 promoter is dependent on SB . As determined by primer extension studies, the 5 end of the SB -initiated mRNA synthesized in vitro from the sar P3 promoter is in agreement with the 5 end of the cellular RNA.In prokaryotes, several factors coexist in cells (19,22,24). The transcription factors evolutionarily related to Escherichia coli 70 are subdivided into two groups (15).…”

“…B , identified in sporulating Bacillus subtilis, is the first member of the alternate factors to be reported in prokaryotes (20,21). Much has been learnt recently about the regulation of expression of the sigB operon and the modulation of the function of the SigB ( B ) protein in response to changing stress (entry into stationary growth phase, nutrient depletion, and presence of uncouplers of oxidative phosphorylation) and environmental stress (heat shock and osmotic shock) in B. subtilis (2,6,8,22,36,37,41).The emergence of multiple-drug-resistant, highly pathogenic strains of Staphylococcus aureus poses a serious threat for human and animal health management of infected subjects. S. aureus causes a number of infections ranging from superficial skin abscesses to life-threatening systemic diseases (e.g., toxic shock syndrome and osteomyelitis) (17,25,38).…”

“…In prokaryotes, several factors coexist in cells (19,22,24). The transcription factors evolutionarily related to Escherichia coli 70 are subdivided into two groups (15).…”

The Bacillus subtilis rsbU gene product is necessary for RsbX-dependent regulation of sigma B

“…B is a secondary sigma factor of Bacillus subtilis (14). Genes that rely on B for their expression are induced when B. subtilis ceases exponential growth in rich, sporulation-suppressing media or is exposed to any of several environmental insults (e.g., heat, salt, or ethanol) (2, 4, 7-10, 16, 25, 26).…”