Download or read book Regulation of Ribonucleotide Reductase Expression in Escherichia Coli written by Blake Alan Jacobson and published by . This book was released on 1993 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of Ribonucleotide Reductase Expression in Escherichia Coli written by Lance Bischoff Augustin and published by . This book was released on 1992 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of Gene Expression in Escherichia coli written by E. C. C. Lin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date guide focuses on the understanding of key regulatory mechanisms governing gene expression in Escherichia coli. Studies of E. coli not only provide the first models of gene regulation, but research continues to yield different control mechanisms.

Download or read book Regulation of E Coli Nrd Operon Encoding Ribonucleotide Reductase written by Lei Sun and published by . This book was released on 1993 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of Ribonucleotide Reductase MRNA Synthesis in Escherichia Coli written by Christopher Keith Tuggle and published by . This book was released on 1986 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of Ribonucleoside Diphosphate Reductase MRNA Synthesis in Escherichia Coli written by Paul David Hanke and published by . This book was released on 1983 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transcriptional Regulation of the Escherichia Coli K 12 Grx Gene written by Weiyin Shen and published by . This book was released on 1997 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of Ribonucleotide Reductase Expression in Escherichia Coli written by Blake Alan Jacobson and published by . This book was released on 1997 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Novel Aspects of the Response to Nitric Oxide in Escherichia Coli written by Shivani Chhabra and published by . This book was released on 2016 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bacteria are exposed to reactive nitrogen and oxygen species produced exogenously (including by the host immune system) or endogenously. The focus of this study is the role of the repressor NsrR in the response to nitrosative stress, and regulation of expression of the nitric oxide (NO) inducible Class Ib ribonucleotide reductase in Escherichia coli. Reaction of the [Fe-S] cluster of NsrR with NO leads to de-repression of NsrR targets, which include the gene encoding an NO scavenging flavohemoglobin. Here we show that nsrR is expressed from a strong promoter, but that its translation is extremely inefficient, leading to a low cellular NsrR concentration. Conversion of the nsrR start codon from the wild type GUG to AUG increased the efficiency of translation and had measurable effects on the expression patterns of some NsrR-regulated genes. Expression profiling showed that genes regulated by NsrR (whether directly or indirectly) tend to express lower mRNA levels when the nsrR start codon is AUG than when it is GUG. We conclude that NsrR abundance in the cell is poised in such a way that promoters with low-affinity NsrR binding sites may partially escape NsrR-mediated repression. Transcriptomics data implicated the pyruvate oxidase gene poxB as a novel NsrR target, which we showed to be due to read-through transcription from the upstream hcp-hcr genes. We also present evidence to suggest that NsrR is a regulator of the sufABCDSE genes, which encode the components of an [Fe-S] cluster biogenesis and repair system. Ribonucleotide reductases (RNRs) are required for the de novo synthesis of deoxyribonucleotides by the reduction of 2′ -OH of ribonucleotides. We examined the regulation of the nrdHIEF operon encoding a Class Ib RNR. We showed that up-regulation of nrdHIEF in response to NO and oxidative stress is mediated by Fur and NrdR, respectively. We also present preliminary results that suggest that a small RNA and the RNA chaperone Hfq might have a role to play in the regulation of nrdHIEF expression. We also found that a partially symmetrical GC rich sequence (CG-CGCG-N6-CGCG-CG) in the 5′-UTR of nrdH has a strong effect on nrdH expression, mainly post-transcriptionally.

Download or read book Regulation of Several Genes Involved in DNA Replication in Escherichia Coli written by Thomas David Daws and published by . This book was released on 1988 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reaction Mechanism and Allosteric Regulation of Class Ia Ribonucleotide Reductase from Escherichia Coli written by Alex Kasrayan and published by . This book was released on 2004 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Regulation of Nitrate Responsive Genes in Escherichia Coli written by Tassia Kolesnikow and published by . This book was released on 1994 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Vivo Cofactor Biosynthesis and Maintenance in the Class Ia Ribonucleotide Reductase Small Subunit of Escherichia Coli written by Chia-Hung Wu (Ph. D.) and published by . This book was released on 2009 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The small subunit ([beta]2) of Escherichia coli class Ia ribonucleotide reductases (RNRs) contains a diferric tyrosyl radical (Y*) cofactor essential for the conversion of nucleotides to deoxynucleotides that are needed for DNA synthesis and repair. The mechanism and factors involved in the biosynthesis, maintenance and regulation of this cluster remains unclear. To understand these pathways, the genes contiguous to nrdB (gene encoding [beta]) in 181 bacterial genomes were analyzed which revealed a highly conserved [2Fe2S]-ferredoxin, YfaE in E. coli. YfaE has been cloned, expressed, reconstituted, and characterized by UV-visible, EPR and Mössbauer spectroscopies. Titration of met-[beta]2 (an inactive diferric-[beta]2 with Y* reduced) with [2Fe2S]1+-YfaE results in formation of diferrous-[beta]2 with one Fe reduced/YfaE oxidized. At the end point of titration, exposure of the reduced cluster to O2 in the absence of an additional reducing equivalent yields the diferric-Y* with 2 Fe/Y* generated, suggesting that the reducing equivalent required for cluster assembly is supplied by [beta]2, likely by W48. The kobs for the reaction between met-[beta]2 and [2Fe2S]1+-YfaE determined by anaerobic stopped flow spectroscopy is ~1-5 s-1. Studies of conserved Lys to Ala mutations of [beta]2 indicate electrostatic interactions may play an important role for interaction with YfaE. Quantitative Western blots of the whole cells suggest that YfaE acts catalytically in reactivating met-[beta]2 in vivo. Titration experiments establish that met-[beta]2 can be reduced by catalytic amounts of YfaE, Fre (a flavin reductase) and flavin with consumption of NADPH. In the presence of a Y* scavenger, hydroxyurea, [delta]yfaE shows slower growth rates than the isogenic wt strain and Western blots analysis shows up-regulation of YfaE expression, supporting YfaE's role in the reactivation of diferric-[beta]2 in vivo. To investigate the iron sources for diferric-Y* assembly, changes in Fe pools inside the cell subsequent to expression of [beta]2 was monitored by whole cell Mössbauer spectroscopy. The results show that both Fe2+ and Fe3+ pools can provide the iron for cluster assembly, suggesting a reduction mechanism(s) for Fe3+ to allow it function in this capacity. A potential role of YfaE as an iron chaperone for iron delivery to [beta]2 has also been investigated.

Download or read book Regulation of RRNA Gene Expression in Escherichia Coli written by Fatma Serap Aksoy and published by . This book was released on 1982 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of RRNA Expression in Escherichia Coli Under Conditions of Changing Growth Phase and Growth Rate written by Jeremy Alexander Appleman and published by . This book was released on 1998 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure Function Studies of Ribonucleotide Reductase from Escherichia Coli written by Åke Larsson and published by . This book was released on 1990 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Regulation of the Escherichia Coli Nrd Operons by NrdR written by Sowmya Somashekar Reddy and published by . This book was released on 2010 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ribonucleotide reductase (RNR) is the critical enzyme in most organisms that catalyses the synthesis of deoxyribonucleotides (dNTPs). In E. coli there are three RNR operons: nrdAB , nrdHIEF and nrdDG . NrdR is a conserved transcriptional repressor of the operons encoding RNR in many organisms. Previously it has been shown that the nrdHIEF operon of E. coli is induced under oxidative and nitrosative stress conditions, but the molecular mechanism of this induction is not known. The study describes the link between NrdR and low dNTP levels and the possible regulatory mechanisms of the nrdHIEF operon. Evidence is presented to suggest that NrdR may be a sensor of low dNTPs levels. A striking result obtained is that the nrdHIEF operon may also be regulated by a small RNA whose origin still remains unknown. Lastly, it is shown that the spacing between the NrdR boxes in nrdHIEF promoter is important and may be involved in a formation of a loop to achieve repression.