scholarly journals Direct inhibition of transcription in vitro by the isolated N-terminal domain of the Escherichia coli nucleoid-associated protein H-NS and by its paralogue Hha

Microbiology ◽  
2019 ◽  
Vol 165 (4) ◽  
pp. 463-474
Author(s):  
Rajvardhan M. Kapshikar ◽  
J. Gowrishankar
Keyword(s):  
Escherichia Coli ◽  
Direct Inhibition ◽  
Terminal Domain ◽  
Transcription In Vitro

scholarly journals Posttranscriptional Activation of the Transcriptional Activator Rob by Dipyridyl in Escherichia coli

2002 ◽  
Vol 184 (5) ◽  
pp. 1407-1416 ◽  
Author(s):  
Judah L. Rosner ◽  
Bindi Dangi ◽  
Angela M. Gronenborn ◽  
Robert G. Martin
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Transcriptional Activator ◽  
Terminal Domain ◽  
Activation Of Transcription ◽  
Transcription In Vitro ◽  
Activity State ◽  
Low Activity

ABSTRACT The transcriptional activator Rob consists of an N-terminal domain (NTD) of 120 amino acids responsible for DNA binding and promoter activation and a C-terminal domain (CTD) of 169 amino acids of unknown function. Although several thousand molecules of Rob are normally present per Escherichia coli cell, they activate promoters of the rob regulon poorly. We report here that in cells treated with either 2,2"- or 4,4"-dipyridyl (the latter is not a metal chelator), Rob-mediated transcription of various rob regulon promoters was increased substantially. A small, growth-phase-dependent effect of dipyridyl on the rob promoter was observed. However, dipyridyl enhanced Rob's activity even when rob was regulated by a heterologous (lac) promoter showing that the action of dipyridyl is mainly posttranscriptional. Mutants lacking from 30 to 166 of the C-terminal amino acids of Rob had basal levels of activity similar to that of wild-type cells, but dipyridyl treatment did not enhance this activity. Thus, the CTD is not an inhibitor of Rob but is required for activation of Rob by dipyridyl. In contrast to its relatively low activity in vivo, Rob binding to cognate DNA and activation of transcription in vitro is similar to that of MarA, which has a homologous NTD but no CTD. In vitro nuclear magnetic resonance studies demonstrated that 2,2"-dipyridyl binds to Rob but not to the CTD-truncated Rob or to MarA, suggesting that the effect of dipyridyl on Rob is direct. Thus, it appears that Rob can be converted from a low activity state to a high-activity state by a CTD-mediated mechanism in vivo or by purification in vitro.

scholarly journals Analysis of MinC Reveals Two Independent Domains Involved in Interaction with MinD and FtsZ

2000 ◽  
Vol 182 (14) ◽  
pp. 3965-3971 ◽  
Author(s):  
Zonglin Hu ◽  
Joe Lutkenhaus
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Functional Domains ◽  
Wild Type ◽  
Terminal Domain ◽  
Ring Assembly ◽  
Z Ring ◽  
Ftsz Assembly

ABSTRACT In Escherichia coli FtsZ assembles into a Z ring at midcell while assembly at polar sites is prevented by themin system. MinC, a component of this system, is an inhibitor of FtsZ assembly that is positioned within the cell by interaction with MinDE. In this study we found that MinC consists of two functional domains connected by a short linker. When fused to MalE the N-terminal domain is able to inhibit cell division and prevent FtsZ assembly in vitro. The C-terminal domain interacts with MinD, and expression in wild-type cells as a MalE fusion disrupts minfunction, resulting in a minicell phenotype. We also find that MinC is an oligomer, probably a dimer. Although the C-terminal domain is clearly sufficient for oligomerization, the N-terminal domain also promotes oligomerization. These results demonstrate that MinC consists of two independently functioning domains: an N-terminal domain capable of inhibiting FtsZ assembly and a C-terminal domain responsible for localization of MinC through interaction with MinD. The fusion of these two independent domains is required to achieve topological regulation of Z ring assembly.

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 Mutational Analysis of the Chlamydia trachomatis rRNA P1 Promoter Defines Four Regions Important for Transcription In Vitro

1998 ◽  
Vol 180 (9) ◽  
pp. 2359-2366 ◽  
Author(s):  
Ming Tan ◽  
Tamas Gaal ◽  
Richard L. Gourse ◽  
Joanne N. Engel
Keyword(s):  
Escherichia Coli ◽  
Chlamydia Trachomatis ◽  
Rna Polymerase ◽  
Mutational Analysis ◽  
In Vitro Transcription ◽  
Rna Polymerases ◽  
Rich Region ◽  
E Coli ◽  
Transcription In Vitro

ABSTRACT We have characterized the Chlamydia trachomatisribosomal promoter, rRNA P1, by measuring the effect of substitutions and deletions on in vitro transcription with partially purifiedC. trachomatis RNA polymerase. Our analyses indicate that rRNA P1 contains potential −10 and −35 elements, analogous toEscherichia coli promoters recognized by E-ς70. We identified a novel AT-rich region immediately downstream of the −35 region. The effect of this region was specific for C. trachomatis RNA polymerase and strongly attenuated by single G or C substitutions. Upstream of the −35 region was an AT-rich sequence that enhanced transcription by C. trachomatis and E. coli RNA polymerases. We propose that this region functions as an UP element.

Termination of transcription in vitro in the escherichia coli tryptophan operon leader region

1976 ◽  
Vol 103 (2) ◽  
pp. 383-393 ◽  
Author(s):  
Frank Lee ◽  
Catherine L. Squires ◽  
Craig Squires ◽  
Charles Yanofsky
Keyword(s):  
Escherichia Coli ◽  
Leader Region ◽  
Tryptophan Operon ◽  
Transcription In Vitro

scholarly journals Autonomous Role of 3′-Terminal CCCA in Directing Transcription of RNAs by Qβ Replicase

2001 ◽  
Vol 75 (23) ◽  
pp. 11373-11383 ◽  
Author(s):  
David M. Tretheway ◽  
Shigeo Yoshinari ◽  
Theo W. Dreher
Keyword(s):  
Escherichia Coli ◽  
Secondary Structure ◽  
Similar Sequence ◽  
Transcriptional Initiation ◽  
Template Sequence ◽  
Transcription In Vitro ◽  
Internal Initiation

ABSTRACT We have studied transcription in vitro by Qβ replicase to deduce the minimal features needed for efficient end-to-end copying of an RNA template. Our studies have used templates ca. 30 nucleotides long that are expected to be free of secondary structure, permitting unambiguous analysis of the role of template sequence in directing transcription. A 3′-terminal CCCA (3′-CCCA) directs transcriptional initiation to opposite the underlined C; the amount of transcription is comparable between RNAs possessing upstream (CCA) n tracts, A-rich sequences, or a highly folded domain and is also comparable in single-round transcription assays to transcription of two amplifiable RNAs. Predominant initiation occurs within the 3′-CCCA initiation box when a wide variety of sequences is present immediately upstream, but CCA or a closely similar sequence in that position results in significant internal initiation. Removal of the 3′-A from the 3′-CCCA results in 5- to 10-fold-lower transcription, emphasizing the importance of the nontemplated addition of 3′-A by Qβ replicase during termination. In considering whether 3′-CCCA could provide sufficient specificity for viral transcription, and consequently amplification, in vivo, we note that tRNAHis is the only stable Escherichia coliRNA with 3′-CCCA. In vitro-generated transcripts corresponding to tRNAHis served as poor templates for Qβ replicase; this was shown to be due to the inaccessibility of the partially base-paired CCCA. These studies demonstrate that 3′-CCCA plays a major role in the control of transcription by Qβ replicase and that the abundant RNAs present in the host cell should not be efficient templates.

scholarly journals Determinants of the C-Terminal Domain of the Escherichia coli RNA Polymerase α Subunit Important for Transcription at Class I Cyclic AMP Receptor Protein-Dependent Promoters

2002 ◽  
Vol 184 (8) ◽  
pp. 2273-2280 ◽  
Author(s):  
Nigel J. Savery ◽  
Georgina S. Lloyd ◽  
Stephen J. W. Busby ◽  
Mark S. Thomas ◽  
Richard H. Ebright ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Rna Polymerase ◽  
Class Ii ◽  
Class I ◽  
Receptor Protein ◽  
Α Subunit ◽  
Cyclic Amp Receptor Protein ◽  
Terminal Domain

ABSTRACT Alanine scanning of the Escherichia coli RNA polymerase α subunit C-terminal domain (αCTD) was used to identify amino acid side chains important for class I cyclic AMP receptor protein (CRP)-dependent transcription. Key residues were investigated further in vivo and in vitro. Substitutions in three regions of αCTD affected class I CRP-dependent transcription from the CC(−61.5) promoter and/or the lacP1 promoter. These regions are (i) the 287 determinant, previously shown to contact CRP during class II CRP-dependent transcription; (ii) the 265 determinant, previously shown to be important for αCTD-DNA interactions, including those required for class II CRP-dependent transcription; and (iii) the 261 determinant. We conclude that CRP contacts the same target in αCTD, the 287 determinant, at class I and class II CRP-dependent promoters. We also conclude that the relative contributions of individual residues within the 265 determinant depend on promoter sequence, and we discuss explanations for effects of substitutions in the 261 determinant.

scholarly journals An Atypical KdpD Homologue from the Cyanobacterium Anabaena sp. Strain L-31: Cloning, In Vivo Expression, and Interaction with Escherichia coli KdpD-CTD

2005 ◽  
Vol 187 (14) ◽  
pp. 4921-4927 ◽  
Author(s):  
Anand Ballal ◽  
Marc Bramkamp ◽  
Hema Rajaram ◽  
Petra Zimmann ◽  
Shree Kumar Apte ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Response Regulator ◽  
Nitrilotriacetic Acid ◽  
Soluble Form ◽  
Filamentous Cyanobacterium ◽  
E Coli ◽  
Transmembrane Segments ◽  
Terminal Domain

ABSTRACT The kdpFABC operon of Escherichia coli, coding for the high-affinity K+ transport system KdpFABC, is transcriptionally regulated by the products of the adjacently located kdpDE genes. The KdpD protein is a membrane-bound sensor kinase consisting of a large N-terminal domain and a C-terminal transmitter domain interconnected by four transmembrane segments (the transmembrane segments together with the C-terminal transmitter domain of KdpD are referred to as CTD), while KdpE is a cytosolic response regulator. We have cloned and sequenced the kdp operon from a nitrogen-fixing, filamentous cyanobacterium, Anabaena sp. strain L-31 (GenBank accession. number AF213466 ). The kdpABC genes are similar in size to those of E. coli, but the kdpD gene is short (coding only for 365 amino acids), showing homology only to the N-terminal domain of E. coli KdpD. A kdpE-like gene is absent in the vicinity of this operon. Anabaena KdpD with six C-terminal histidines was overproduced in E. coli and purified by Ni2+-nitrilotriacetic acid affinity chromatography. With antisera raised against the purified Anabaena KdpD, the protein was detected in Anabaena sp. strain L-31 membranes. The membrane-associated or soluble form of the Anabaena KdpD(6His) could be photoaffinity labeled with the ATP analog 8-azido-ATP, indicating the presence of an ATP binding site. The coproduction of Anabaena KdpD with E. coli KdpD-CTD decreased E. coli kdpFABC expression in response to K+ limitation in vivo relative to the wild-type KdpD-CTD protein. In vitro experiments revealed that the kinase activity of the E. coli KdpD-CTD was unaffected, but its phosphatase activity increased in the presence of Anabaena KdpD(6His). To our knowledge this is the first report where a heterologous N-terminal domain (Anabaena KdpD) is shown to affect in trans KdpD-CTD (E. coli) activity, which is just opposite to that observed for the KdpD-N-terminal domain of E. coli.

Sign in / Sign up

Export Citation Format

Share Document