scholarly journals Genomics of DNA cytosine methylation in Escherichia coli reveals its role in stationary phase transcription

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Christina Kahramanoglou ◽  
Ana I. Prieto ◽  
Supriya Khedkar ◽  
Bettina Haase ◽  
Ankur Gupta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Cytosine Methylation ◽  
Dna Cytosine Methylation

scholarly journals DNA cytosine methylation at the lexA promoter of Escherichia coli is stationary phase specific

2021 ◽  
Author(s):  
Elizabeth B Lewis ◽  
Edwin Chen ◽  
Matthew J Culyba
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Cytosine Methylation ◽  
Sos Response ◽  
Phase Growth ◽  
Bacterial Dna ◽  
Cytosine Methyltransferase ◽  
Lexa Binding ◽  
The Impact ◽  
Dna Damage Response Pathway

Abstract The bacterial DNA damage response pathway (SOS response) is composed of a network of genes regulated by a single transcriptional repressor, LexA. The lexA promoter, itself, contains two LexA operators, enabling negative feedback. In Escherichia coli, the downstream operator contains a conserved DNA cytosine methyltransferase (Dcm) site that is predicted to be methylated to 5-methylcytosine (5mC) specifically during stationary phase growth, suggesting a regulatory role for DNA methylation in the SOS response. To test this, we quantified 5mC at the lexA locus, and then examined the effect of LexA on Dcm activity, as well as the impact of this 5mC mark on LexA binding, lexA transcription, and SOS response induction. We found that 5mC at the lexA promoter is specific to stationary phase growth, but that it does not affect lexA expression. Our data support a model where LexA binding at the promoter inhibits Dcm activity without an effect on the SOS regulon.

scholarly journals Loss of DNA cytosine methylation increases ethidium bromide resistance in Escherichia coli (800.4)

2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Alexandra Mandarano ◽  
Olga Varechtchouk ◽  
Robert Simon ◽  
Kevin Militello
Keyword(s):  
Escherichia Coli ◽  
Ethidium Bromide ◽  
Cytosine Methylation ◽  
Dna Cytosine Methylation

Analysis of DNA Cytosine Methylation between the Non-pollinated and Pollinated Ovaries of Cymbidium hybridium(Orchidaceae) Based on MSAP

2009 ◽  
Vol 30 (4) ◽  
pp. 464-470 ◽  
Author(s):  
Xiao-Qiang CHEN ◽  
Chun-Guo WANG ◽  
Xiu-Lan LI ◽  
Wen-Qin SONG ◽  
Rui-Yang CHEN
Keyword(s):  
Cytosine Methylation ◽  
Dna Cytosine Methylation

scholarly journals Adaptive reversion of a frameshift mutation in Escherichia coli.

Genetics ◽  
1991 ◽  
Vol 128 (4) ◽  
pp. 695-701 ◽  
Author(s):  
J Cairns ◽  
P L Foster
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Exponential Growth ◽  
Frameshift Mutation ◽  
Rare Event ◽  
Lacz Fusion ◽  
Mutation Rates ◽  
Classical Studies ◽  
Selective Forces

Abstract Mutation rates are generally thought not to be influenced by selective forces. This doctrine rests on the results of certain classical studies of the mutations that make bacteria resistant to phages and antibiotics. We have studied a strain of Escherichia coli which constitutively expresses a lacI-lacZ fusion containing a frameshift mutation that renders it Lac-. Reversion to Lac+ is a rare event during exponential growth but occurs in stationary cultures when lactose is the only source of energy. No revertants accumulate in the absence of lactose, or in the presence of lactose if there is another, unfulfilled requirement for growth. The mechanism for such mutation in stationary phase is not known, but it requires some function of RecA which is apparently not required for mutation during exponential growth.

scholarly journals Plasmid DNA Supercoiling and Gyrase Activity in Escherichia coli Wild-Type and rpoS Stationary-Phase Cells

2003 ◽  
Vol 185 (3) ◽  
pp. 1097-1100 ◽  
Author(s):  
Yazmid Reyes-Domínguez ◽  
Gabriel Contreras-Ferrat ◽  
Jesús Ramírez-Santos ◽  
Jorge Membrillo-Hernández ◽  
M. Carmen Gómez-Eichelmann
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Plasmid Dna ◽  
Bimodal Distribution ◽  
Dna Supercoiling ◽  
Wild Type

ABSTRACT Stationary-phase cells displayed a distribution of relaxed plasmids and had the ability to recover plasmid supercoiling as soon as nutrients became available. Preexisting gyrase molecules in these cells were responsible for this recovery. Stationary-phase rpoS cells showed a bimodal distribution of plasmids and failed to supercoil plasmids after the addition of nutrients, suggesting that rpoS plays a role in the regulation of plasmid topology during the stationary phase.

Mannose-Binding Activity of Escherichia coli: a Determinant of Attachment and Ingestion of the Bacteria by Macrophages

1980 ◽  
Vol 29 (2) ◽  
pp. 417-424
Author(s):  
Zvi Bar-Shavit ◽  
Rachel Goldman ◽  
Itzhak Ofek ◽  
Nathan Sharon ◽  
David Mirelman
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Pathogenic Bacteria ◽  
Binding Activity ◽  
Exponential Phase ◽  
Restrictive Temperature ◽  
Filamentous Bacteria ◽  
Phagocytic Cells ◽  
E Coli ◽  
Mannose Binding

Recently, it was suggested that a mannose-specific lectin on the bacterial cell surface is responsible for the recognition by phagocytic cells of certain nonopsonized Escherichia coli strains. In this study we assessed the interaction of two strains of E. coli at different phases of growth with a monolayer of mouse peritoneal macrophages and developed a direct method with [ 14 C]mannan to quantitate the bacterial mannose-binding activity. Normal-sized bacteria were obtained from logarithmic and stationary phases of growth. Nonseptated filamentous cells were formed by growing the organisms in the presence of cephalexin or at a restrictive temperature. Attachment to macrophages of all bacterial forms was inhibited by methyl α- d -mannoside and mannan but not by other sugars tested. The attachment of stationary phase and filamentous bacteria to macrophages, as well as their mannose-binding activity, was similar, whereas in the exponential-phase bacteria they were markedly reduced. The results show a linear relation between the two parameters ( R = 0.98, P < 0.001). The internalization of the filamentous cells attached to macrophages during 45 min of incubation was much less efficient (20%) compared to that of exponential-phase, stationary-phase, or antibody-coated filamentous bacteria (90%). The results indicate that the mannose-binding activity of E. coli determines the recognition of the organisms by phagocytes. They further suggest that administration of β-lactam antibiotics may impair elimination of certain pathogenic bacteria by inducing the formation of filaments which are inefficiently internalized by the host's phagocytic cells.

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