Homochiral synthesis of an aza analogue of S-adenosyl-L-methionine (AdoMet) and its binding to the E. coli methionine repressor protein (MetJ)

1996 ◽  
pp. 791 ◽  
Author(s):  
Mark J. Thompson ◽  
Abdelaziz Mekhalfia ◽  
David L. Jakeman ◽  
Simon E. V. Phillips ◽  
Kathryn Phillips ◽  
...  
Keyword(s):  
Repressor Protein ◽  
E Coli

Synthesis of an aza-analogue of S-adenosyl-L-methionine and its binding to the E. coli methionine repressor protein (MetJ)

1996 ◽  
Vol 61 (s1) ◽  
pp. 85-87
Author(s):  
Mark J. Thompson ◽  
Abdelaziz Mekhalfia ◽  
David L. Jakeman ◽  
Simon E. V. Phillips ◽  
Kathryn Phillips ◽  
...  
Keyword(s):  
Repressor Protein ◽  
E Coli

Structural studies of protein–nucleic acid interaction: the sources of sequence-specific binding

1990 ◽  
Vol 23 (3) ◽  
pp. 205-280 ◽  
Author(s):  
Thomas A. Steitz
Keyword(s):  
Dna Binding ◽  
Crystal Structures ◽  
Binding Proteins ◽  
Regulatory Protein ◽  
Dna Binding Proteins ◽  
Structural Studies ◽  
Klenow Fragment ◽  
Proteolytic Fragment ◽  
Repressor Protein ◽  
E Coli

Structural studies of DNA-binding proteins and their complexes with DNA have proceeded at an accelerating pace in recent years due to important technical advances in molecular genetics, DNA synthesis, protein crystallography and nuclear magnetic resonance. The last major review on this subject by Pabo & Sauer (1984) summarized the structural and functional studies of the three sequence-specific DNA-binding proteins whose crystal structures were then known, the E. coli catabolite gene activator protein (CAP) (McKay & Steitz, 1981; McKay et al. 1982; Weber & Steitz, 1987), a cro repressor from phage λ (Anderson et al. 1981), and the DNA-binding proteolytic fragment of λcI repressor protein (Pabo & Lewis, 1982) Although crystallographic studies of the E. coli lac repressor protein were initiated as early as 1971 when it was the only regulatory protein available in sufficient quantities for structural studies (Steitz et al. 1974), little was established about the structural aspects of DNA-binding proteins until the structure of CAP was determined in 1980 followed shortly thereafter by the structure of λcro repressor and subsequently that of the λ repressor fragment. There are now determined at high resolution the crystal structures of seven prokaryotic gene regulatory proteins or fragments [CAP, λcro, λcI repressor fragment, 434 repressor fragment (Anderson et al. 1987), 434 cro repressor (Wolberger et al. 1988), E. coli trp repressor (Schevitz et al. 1985), E. coli met repressor (Rafferty et al. 1989)], EcoR I restriction endonuclease (McClarin et al. 1986), DNAse I (Suck & Ofner, 1986), the catalytic domain of γδ resolvase (Hatfull et al. 1989) and two sequence-independent double-stranded DNA-binding proteins [the Klenow fragment of E. coli DNA polymerase I (Ollis et al. 1985) and the E. coli Hu protein (Tanaka et al., 1984)].

scholarly journals Nonnative Proteins Induce Expression of the Bacillus subtilis CIRCE Regulon

1998 ◽  
Vol 180 (11) ◽  
pp. 2895-2900 ◽  
Author(s):  
Axel Mogk ◽  
Andrea Völker ◽  
Susanne Engelmann ◽  
Michael Hecker ◽  
Wolfgang Schumann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Heat Shock ◽  
Bacterial Species ◽  
Negative Control ◽  
Expression Level ◽  
Ethanol Stress ◽  
Transcriptional Fusion ◽  
Repressor Protein ◽  
E Coli

ABSTRACT The chaperone-encoding groESL and dnaKoperons constitute the CIRCE regulon of Bacillus subtilis. Both operons are under negative control of the repressor protein HrcA, which interacts with the CIRCE operator and whose activity is modulated by the GroESL chaperone machine. In this report, we demonstrate that induction of the CIRCE regulon can also be accomplished by ethanol stress and puromycin. Introduction of the hrcA gene and a transcriptional fusion under the control of the CIRCE operator intoEscherichia coli allowed induction of this fusion by heat shock, ethanol stress, and overproduction of GroESL substrates. The expression level of this hrcA-bgaB fusion inversely correlated with the amount of GroE machinery present in the cells. Therefore, all inducing conditions seem to lead to induction via titration of the GroE chaperonins by the increased level of nonnative proteins formed. Puromycin treatment failed to induce the ςB-dependent general stress regulon, indicating that nonnative proteins in general do not trigger this response. Reconstitution of HrcA-dependent heat shock regulation of B. subtilis in E. coli and complementation of E. coli groESL mutants by B. subtilis groESL indicate that the GroE chaperonin systems of the two bacterial species are functionally exchangeable.

ChemInform Abstract: Homochiral Synthesis of an Aza Analogue of S-Adenosyl-L-methionine ( AdoMet) and Its Binding to the E. coli Methionine Repressor Protein ( MetJ).

ChemInform ◽  
2010 ◽  
Vol 27 (36) ◽  
pp. no-no
Author(s):  
M. J. THOMPSON ◽  
A. MEKHALFIA ◽  
D. L. JAKEMAN ◽  
S. E. V. PHILLIPS ◽  
K. PHILLIPS ◽  
...  
Keyword(s):  
Repressor Protein ◽  
E Coli

scholarly journals Comparative analysis of the QUTR transcription repressor protein and the three C-terminal domains of the pentafunctional AROM enzyme

1996 ◽  
Vol 313 (3) ◽  
pp. 941-950 ◽  
Author(s):  
Heather K. LAMB ◽  
Jonathan D. MOORE ◽  
Jeremy H. LAKEY ◽  
Lisa J. LEVETT ◽  
Kerry A. WHEELER ◽  
...  
Keyword(s):  
Tertiary Structure ◽  
Guanidine Hydrochloride ◽  
Fluorescence Emission ◽  
Shikimate Dehydrogenase ◽  
Sequence Alignments ◽  
Repressor Protein ◽  
E Coli ◽  
Domain Protein ◽  
Dehydroquinate Synthase ◽  
Terminal Domains

The AROM protein is a pentadomain protein catalysing steps two to six in the prechorismate section of the shikimate pathway in microbial eukaryotes. On the basis of amino acid sequence alignments and the properties of mutants unable to utilize quinic acid as a carbon source, the AROM protein has been proposed to be homologous throughout its length with the proteins regulating transcription of the genes necessary for quinate catabolism. The QUTR transcription repressor protein has been proposed to be homologous with the three C-terminal domains of the AROM protein and one-fifth of the penultimate N-terminal domain. We report here the results of experiments designed to overproduce the QUTR and AROM proteins and their constituent domains in Escherichia coli, the purpose being to facilitate domain purification and (in the case of AROM), complementation of E. coli aro- mutations in order to probe the degree to which individual domains are stable and functional. The 3-dehydroquinate dehydratase domain of the AROM protein and the 3-dehydroquinate dehydratase-like domain of the QUTR protein were purified in bulk and subjected to comparative CD spectroscopy and fluorescence emission spectroscopy. The CD spectra were found to be virtually superimposable. The fluorescence emission spectra of both domains had the signal from the tryptophan residues almost completely quenched, giving a tyrosine-dominated spectrum for both the AROM- and QUTR-derived domains. This unexpected observation was demonstrated to be due to a highly unusual environment provided by the tertiary structure, as addition of the denaturant guanidine hydrochloride gave a typical tryptophan-dominated spectrum for both domains. The spectroscopy experiments had the potential to refute the biologically-based proposal for a common origin for the AROM and QUTR proteins; however, the combined biophysical data are consistent with the hypothesis. We have previously reported that the AROM dehydroquinate synthase and 3-dehydroquinate dehydratase are stable and functional as individual domains, but that the 5-enol-pyruvylshikimate-3-phosphate synthase is only active as part of the complete AROM protein or as a bi-domain fragment with dehydroquinate synthase. Here we report that the aromA gene (encoding the AROM protein) of Aspergillus nidulans contains a 53 nt intron in the extreme C-terminus of the shikimate dehydrogenase domain. This finding accounts for the previously reported observation that the AROM protein was unable to complement aroE- (lacking shikimate dehydrogenase) mutations in E. coli. When the intron is removed the correctly translated AROM protein is able to complement the E. coli aroE- mutation. An AROM-derived shikimate dehydrogenase domain is, however, non-functional, but function is restored in a bi-domain protein with 3-dehydroquinate dehydratase. This interaction is not entirely specific, as substitution of the 3-dehydroquinate dehydratase domain with the glutathione S-transferase protein partially restores enzyme activity. Similarly an AROM-derived shikimate kinase domain is non-functional, but is functional as part of the complete AROM protein, or as a bi-domain protein with 3-dehydroquinate dehydratase.

Endotoxin Alteration of the Mucopolysaccharide Blood Vessel Coating in Rats

1974 ◽  
Vol 32 ◽  
pp. 148-149
Author(s):  
D. E. Philpott ◽  
A. Takahashi
Keyword(s):  
Skeletal Muscle ◽  
Endothelial Cells ◽  
Salivary Gland ◽  
Carotid Artery ◽  
Basement Membrane ◽  
Coronary Vessels ◽  
Ruthenium Red ◽  
E Coli ◽  
Old Rats ◽  
The Brain

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

Emigration of neutrophils in the central nervous system

1983 ◽  
Vol 41 ◽  
pp. 788-789
Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Osmium Tetroxide ◽  
White Blood Cells ◽  
Arterial Perfusion ◽  
E Coli ◽  
Intracisternal Injection ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
Interendothelial Junctions

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.

Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

1967 ◽  
Vol 25 ◽  
pp. 136-137
Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Specific Antiserum ◽  
Electron Microscopic ◽  
E Coli ◽  
Cytoplasmic Membranes ◽  
Viral Progeny ◽  
Ultrathin Sections ◽  
Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

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