scholarly journals A Region of ςK Involved in Promoter Activation by GerE in Bacillus subtilis

1999 ◽  
Vol 181 (14) ◽  
pp. 4365-4373 ◽  
Author(s):  
Kathryn H. Wade ◽  
Ghislain Schyns ◽  
Jason A. Opdyke ◽  
Charles P. Moran
Keyword(s):  
Bacillus Subtilis ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Promoter Activity ◽  
Amino Acid Substitutions ◽  
Amino Acid Residues ◽  
Transcription In Vitro ◽  
A Site ◽  
Initial Binding

ABSTRACT During endospore formation in Bacillus subtilis, the DNA binding protein GerE stimulates transcription from several promoters that are used by RNA polymerase containing ςK. GerE binds to a site on one of these promoters, cotX, that overlaps its −35 region. We tested the model that GerE interacts with ςK at the cotX promoter by seeking amino acid substitutions in ςK that interfered with GerE-dependent activation of the cotX promoter but which did not affect utilization of the ςK-dependent, GerE-independent promoter gerE. We identified two amino acid substitutions in ςK, E216K and H225Y, that decrease cotXpromoter utilization but do not affect gerE promoter activity. Alanine substitutions at these positions had similar effects. We also examined the effects of the E216A and H225Y substitutions in ςK on transcription in vitro. We found that these substitutions specifically reduced utilization of the cotXpromoter. These and other results suggest that the amino acid residues at positions 216 and 225 are required for GerE-dependentcotX promoter activity, that the histidine at position 225 of ςK may interact with GerE at the cotXpromoter, and that this interaction may facilitate the initial binding of ςK RNA polymerase to the cotX promoter. We also found that the alanine substitutions at positions 216 and 225 of ςK had no effect on utilization of the GerE-dependent promoter cotD, which contains GerE binding sites that do not overlap with its −35 region.

scholarly journals A Region in Bacillus subtilisςH Required for Spo0A-Dependent Promoter Activity

1998 ◽  
Vol 180 (18) ◽  
pp. 4987-4990 ◽  
Author(s):  
Cindy M. Buckner ◽  
Charles P. Moran
Keyword(s):  
Amino Acids ◽  
Bacillus Subtilis ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Sigma Factor ◽  
Promoter Activity ◽  
Amino Acid Substitutions ◽  
Mutant Form ◽  
Promoter Activation ◽  
Affect Expression

ABSTRACT Spo0A activates transcription in Bacillus subtilis from promoters that are used by two types of RNA polymerase, RNA polymerase containing the primary sigma factor, ςA, and RNA polymerase containing a secondary sigma factor, known as ςH. The region of ςA near positions 356 to 359 is required for Spo0A-dependent promoter activation, possibly because Spo0A interacts with this region of ςA at these promoters. To determine if the amino acids in the corresponding region of ςH are also important in Spo0A-dependent promoter activation, we examined the effects of single alanine substitutions at 10 positions in ςH (201 to 210). Two alanine substitutions in ςH, at glutamine 201 (Q201A) and at arginine 205 (R205A), significantly decreased activity from the Spo0A-dependent, ςH-dependent promoterspoIIA but did not affect expression from the ςH-dependent, Spo0A-independent promoterscitGp2 and spoVG. Therefore, promoter activation by Spo0A requires homologous regions in ςA and ςH. A mutant form of Spo0A, S231F, that suppresses the sporulation defect caused by several amino acid substitutions in ςA did not suppress the sporulation defects caused by the Q201A and R205A substitutions in ςH. This result and others indicate that different surfaces of Spo0A probably interact with ςA and ςH RNA polymerases.

scholarly journals The −10 Region Is a Key Promoter Specificity Determinant for the Bacillus subtilis Extracytoplasmic-Function ς Factors ςX and ςW

2001 ◽  
Vol 183 (6) ◽  
pp. 1921-1927 ◽  
Author(s):  
Jian Qiu ◽  
John D. Helmann
Keyword(s):  
Bacillus Subtilis ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Context Effects ◽  
Promoter Strength ◽  
Binding Properties ◽  
Promoter Specificity ◽  
Dna Binding Properties

ABSTRACT Transcriptional selectivity derives, in large part, from the sequence-specific DNA-binding properties of the ς subunit of RNA polymerase. There are 17 ς factors in Bacillus subtilis which, in general, recognize distinct sets of promoters. However, some ς factors have overlapping promoter selectivity. We hypothesize that the overlap between the regulons activated by the ςX and ςW factors can be explained by overlapping specificity for the −10 region: ςX recognizes −10 elements with the sequence CGAC and ςW recognizes CGTA, while both can potentially recognize CGTC. To test this model, we mutated the ςX-specific autoregulatory site (PX), containing the −10 element CGAC, to either CGTC or GCTA. Conversely, the ςW autoregulatory site (PW) was altered from CGTA to CGTC or CGAC. Transcriptional analyses, both in vitro and in vivo, indicate that changes to the −10 element are sufficient to switch a promoter from the ςX to the ςW regulon or, conversely, from the ςW to the ςX regulon, but context effects clearly play an important role in determining promoter strength. It seems likely that these subtle differences in promoter selectivity derive from amino acid differences in conserved region 2 of ς, which contacts the −10 element. However, we were unable to alter promoter selectivity by replacements of two candidate recognition residues in ςW.

scholarly journals DksA Is Required for Growth Phase-Dependent Regulation, Growth Rate-Dependent Control, and Stringent Control of fis Expression in Escherichia coli

2006 ◽  
Vol 188 (16) ◽  
pp. 5775-5782 ◽  
Author(s):  
Prabhat Mallik ◽  
Brian J. Paul ◽  
Steven T. Rutherford ◽  
Richard L. Gourse ◽  
Robert Osuna
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Growth Phase ◽  
Stationary Growth ◽  
Rate Dependent ◽  
Transcription In Vitro ◽  
State Growth

ABSTRACT DksA is a critical transcription factor in Escherichia coli that binds to RNA polymerase and potentiates control of rRNA promoters and certain amino acid promoters. Given the kinetic similarities between rRNA promoters and the fis promoter (Pfis), we investigated the possibility that DksA might also control transcription from Pfis. We show that the absence of dksA extends transcription from Pfis well into the late logarithmic and stationary growth phases, demonstrating the importance of DksA for growth phase-dependent regulation of fis. We also show that transcription from Pfis increases with steady-state growth rate and that dksA is absolutely required for this regulation. In addition, both DksA and ppGpp are required for inhibition of Pfis promoter activity following amino acid starvation, and these factors act directly and synergistically to negatively control Pfis transcription in vitro. DksA decreases the half-life of the intrinsically short-lived fis promoter-RNA polymerase complex and increases its sensitivity to the concentration of CTP, the predominant initiating nucleotide triphosphate for this promoter. This work extends our understanding of the multiple factors controlling fis expression and demonstrates the generality of the DksA requirement for regulation of kinetically similar promoters.

scholarly journals Lineage-Specific Amino Acid Substitutions in Region 2 of the RNA Polymerase σ Subunit Affect the Temperature of Promoter Opening

2008 ◽  
Vol 190 (8) ◽  
pp. 3088-3092 ◽  
Author(s):  
N. Barinova ◽  
E. Zhilina ◽  
I. Bass ◽  
V. Nikiforov ◽  
A. Kulbachinskiy
Keyword(s):  
Amino Acid ◽  
Rna Polymerase ◽  
Amino Acid Substitutions ◽  
Amino Acid Residues ◽  
Specific Amino Acid ◽  
Promoter Recognition

ABSTRACT Highly conserved amino acid residues in region 2 of the RNA polymerase σ subunit are known to participate in promoter recognition and opening. We demonstrated that nonconserved residues in this region collectively determine lineage-specific differences in the temperature of promoter opening.

scholarly journals Use of a Two-Color Genetic Screen To Identify a Domain of the Global Regulator Lrp That Is Specifically Required forpap Phase Variation

1998 ◽  
Vol 180 (5) ◽  
pp. 1224-1231 ◽  
Author(s):  
Linda Kaltenbach ◽  
Bruce Braaten ◽  
Julie Tucker ◽  
Margareta Krabbe ◽  
David Low
Keyword(s):  
Amino Acid ◽  
Binding Sites ◽  
Phase Variation ◽  
Genetic Screen ◽  
Amino Acid Substitutions ◽  
Wild Type ◽  
Global Regulator ◽  
Transcription In Vitro

ABSTRACT The global regulator Lrp plays a central role as both a repressor and an activator in Pap phase variation. Unlike most other members of the Lrp regulon such as ilvIH, activation ofpapBA transcription requires the coregulator PapI and is methylation dependent. We developed a two-color genetic screen to identify Lrp mutations that inhibit Pap phase variation but still activate ilvIH transcription, reasoning that such mutations might identify PapI binding or methylation-responsive domains. Amino acid substitutions in Lrp at position 126, 133, or 134 greatly reduced the rate of Pap switching from phase off to phase on but had much smaller effects on ilvIH transcription. In vitro analyses indicated that the T134A and E133G Lrp variants maintained affinities for pap and ilvIH DNAs similar to those of wild-type Lrp. In addition, both mutant Lrp’s were as responsive to PapI as wild-type Lrp, evidenced by an increase in affinity forpap Lrp binding sites 4, 5, and 6. Thus, in vitro analyses did not reveal the step(s) in Pap phase variation where these Lrp mutants were inhibited. In vivo analyses showed that both the T134A and E133G Lrp mutants activated transcription of a phase-on-lockedpap derivative containing a mutation in Lrp binding site 3. Further studies indicated that the T134A Lrp mutant was blocked in a step in Pap phase variation that does not involve PapI. Our data suggest that these mutant Lrp’s are defective in a previously unidentified interaction required for the switch from the phase-off to the phase-on pap transcription state.

scholarly journals Uncoupling of initiation and reinitiation rates during HeLa RNA polymerase II transcription in vitro.

1993 ◽  
Vol 13 (8) ◽  
pp. 4572-4577 ◽  
Author(s):  
Y Jiang ◽  
J D Gralla
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Promoter Activity ◽  
Atp Hydrolysis ◽  
Preinitiation Complex ◽  
Transcription In Vitro ◽  
Rna Polymerase Ii Transcription

RNA polymerase II transcription is influenced both by how rapidly a gene is induced and by the rate at which continuous reinitiation occurs after induction. We show here that in vitro the rates of these two critical steps need not be the same. For activator GAL-AH-dependent HeLa transcription, the rate of assembling a preinitiation complex is significantly slower than the rate of reinitiation. Although reinitiation is rapid, it still requires ATP hydrolysis. This unexpected uncoupling of the rates of initiation and reinitiation implies that in regulating mammalian promoter activity, one must consider separately the controls on initiation during induction and the controls on the subsequent reinitiation events.

scholarly journals α-Helix E of Spo0A Is Required for σA- but Not for σH-Dependent Promoter Activation in Bacillus subtilis

2004 ◽  
Vol 186 (4) ◽  
pp. 1078-1083 ◽  
Author(s):  
Amrita Kumar ◽  
James A. Brannigan ◽  
Charles P. Moran
Keyword(s):  
Amino Acids ◽  
Bacillus Subtilis ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Sigma Factor ◽  
Dna Binding Protein ◽  
Single Amino Acid ◽  
Amino Acid Substitutions ◽  
Promoter Activation ◽  
Α Helix

ABSTRACT At the onset of endospore formation in Bacillus subtilis, the DNA binding protein Spo0A activates transcription from two types of promoters. The first type includes the spoIIG and spoIIE promoters, which are used by σA-RNA polymerase, whereas the second type includes the spoIIA promoter, which is used by RNA polymerase containing the secondary sigma factor σH. Previous genetic analyses have identified specific amino acids in α-helix E of Spo0A that are important for activation of Spo0A-dependent, σA-dependent promoters. However, these amino acids are not required for activation of the σH-dependent spoIIA promoter. We now report the effects of additional single-amino-acid substitutions and the effects of deletions in α-helix E. The effects of alanine substitutions revealed one new position (239) in Spo0A that appears to be specifically required for activation of the σA-dependent promoters. Based on the effects of a deletion mutation, we suggest that α-helix E in Spo0A is not directly involved in interaction with σH-RNA polymerase.

Uncoupling of initiation and reinitiation rates during HeLa RNA polymerase II transcription in vitro

1993 ◽  
Vol 13 (8) ◽  
pp. 4572-4577
Author(s):  
Y Jiang ◽  
J D Gralla
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Promoter Activity ◽  
Atp Hydrolysis ◽  
Preinitiation Complex ◽  
Transcription In Vitro ◽  
Rna Polymerase Ii Transcription

RNA polymerase II transcription is influenced both by how rapidly a gene is induced and by the rate at which continuous reinitiation occurs after induction. We show here that in vitro the rates of these two critical steps need not be the same. For activator GAL-AH-dependent HeLa transcription, the rate of assembling a preinitiation complex is significantly slower than the rate of reinitiation. Although reinitiation is rapid, it still requires ATP hydrolysis. This unexpected uncoupling of the rates of initiation and reinitiation implies that in regulating mammalian promoter activity, one must consider separately the controls on initiation during induction and the controls on the subsequent reinitiation events.

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