scholarly journals The sibling sRNAs NgncR_162 and NgncR_163 of Neisseria gonorrhoeae participate in the expression control of metabolic, transport and regulatory proteins

Microbiology ◽  
2017 ◽  
Vol 163 (11) ◽  
pp. 1720-1734 ◽  
Author(s):  
Susanne Bauer ◽  
Jonas Helmreich ◽  
Marie Zachary ◽  
Marc Kaethner ◽  
Elisabeth Heinrichs ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Regulatory Proteins ◽  
Expression Control ◽  
Metabolic Transport

scholarly journals Overproduction of the MtrCDE Efflux Pump in Neisseria gonorrhoeae Produces Unexpected Changes in Cellular Transcription Patterns

2014 ◽  
Vol 59 (1) ◽  
pp. 724-726 ◽  
Author(s):  
Elizabeth A. Ohneck ◽  
Maira Goytia ◽  
Corinne E. Rouquette-Loughlin ◽  
Sandeep J. Joseph ◽  
Timothy D. Read ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Efflux Pump ◽  
Transcriptional Profiling ◽  
Regulatory Proteins ◽  
Drug Efflux ◽  
Content Type ◽  
Genes Encoding ◽  
High Level ◽  
Cellular Transcription ◽  
Global Consequence

ABSTRACTThe global consequence of drug efflux gene overexpression in bacteria has not been specifically analyzed because strains showing high-level expression typically have mutations in genes encoding regulatory proteins that control other genes. Results from a transcriptional profiling study performed with a strain ofNeisseria gonorrhoeaethat is capable of high-level transcription of themtrCDEefflux pump operon independently of control by cognate regulatory proteins revealed that its overexpression has ramifications for systems other than drug efflux.

scholarly journals Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network

2016 ◽  
Vol 198 (16) ◽  
pp. 2180-2191 ◽  
Author(s):  
Chunxiao Yu ◽  
Ryan McClure ◽  
Kathleen Nudel ◽  
Nadine Daou ◽  
Caroline Attardo Genco
Keyword(s):  
Dna Binding ◽  
Neisseria Gonorrhoeae ◽  
Promoter Region ◽  
Dna Binding Protein ◽  
Dna Binding Proteins ◽  
Host Cells ◽  
Regulatory Proteins ◽  
Wild Type ◽  
Content Type ◽  
Large Repertoire

ABSTRACTTheNeisseria gonorrhoeaeferricuptakeregulator (Fur) protein controls expression of iron homeostasis genes in response to intracellular iron levels. In this study, using transcriptome sequencing (RNA-seq) analysis of anN. gonorrhoeaefurstrain, we defined the gonococcal Fur and iron regulons and characterized Fur-controlled expression of an ArsR-like DNA binding protein. We observed that 158 genes (8% of the genome) showed differential expression in response to iron in anN. gonorrhoeaewild-type orfurstrain, while 54 genes exhibited differential expression in response to Fur. The Fur regulon was extended to additional regulators, including NrrF and 13 other small RNAs (sRNAs), and two transcriptional factors. One transcriptional factor, coding for an ArsR-like regulator (ArsR), exhibited increased expression under iron-replete conditions in the wild-type strain but showed decreased expression across iron conditions in thefurstrain, an effect that was reversed in afur-complemented strain. Fur was shown to bind to the promoter region of thearsRgene downstream of a predicted σ70promoter region. Electrophoretic mobility shift assay (EMSA) analysis confirmed binding of the ArsR protein to thenorBpromoter region, and sequence analysis identified two additional putative targets, NGO1411 and NGO1646. A gonococcalarsRstrain demonstrated decreased survival in human endocervical epithelial cells compared to that of the wild-type andarsR-complemented strains, suggesting that the ArsR regulon includes genes required for survival in host cells. Collectively, these results demonstrate that theN. gonorrhoeaeFur functions as a global regulatory protein to repress or activate expression of a large repertoire of genes, including additional transcriptional regulatory proteins.IMPORTANCEGene regulation in bacteria in response to environmental stimuli, including iron, is of paramount importance to both bacterial replication and, in the case of pathogenic bacteria, successful infection. Bacterial DNA binding proteins are a common mechanism utilized by pathogens to control gene expression under various environmental conditions. Here, we show that the DNA binding protein Fur, expressed by the human pathogenNeisseria gonorrhoeae, controls the expression of a large repertoire of genes and extends this regulon by controlling expression of additional DNA binding proteins. One of these proteins, an ArsR-like regulator, was required forN. gonorrhoeaesurvival within host cells. These results show that the Fur regulon extends to additional regulatory proteins, which together contribute to gonococcal mechanisms of pathogenesis.

Toward an alignment of the actin molecule within the actin filament

1983 ◽  
Vol 41 ◽  
pp. 450-451
Author(s):  
P.R. Smith ◽  
W.E. Fowler ◽  
U. Aebi
Keyword(s):  
Actin Filament ◽  
Diffraction Data ◽  
Quantitative Estimate ◽  
Molecular Model ◽  
Quantitative Comparison ◽  
Regulatory Proteins ◽  
Essential Information ◽  
X Ray ◽  
Maximum Resolution ◽  
Lack Of Information

An understanding of the specific interactions of actin with regulatory proteins has been limited by the lack of information about the structure of the actin filament. Molecular actin has been studied in actin-DNase I complexes by single crystal X-ray analysis, to a resolution of about 0.6nm, and in the electron microscope where two dimensional actin sheets have been reconstructed to a maximum resolution of 1.5nm. While these studies have shown something of the structure of individual actin molecules, essential information about the orientation of actin in the filament is still unavailable.The work of Egelman & DeRosier has, however, suggested a method which could be used to provide an initial quantitative estimate of the orientation of actin within the filament. This method involves the quantitative comparison of computed diffraction data from single actin filaments with diffraction data derived from synthetic filaments constructed using the molecular model of actin as a building block. Their preliminary work was conducted using a model consisting of two juxtaposed spheres of equal size.

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