Search results for "binding"

Comparison of DNase, DNA-polymerase and RNA-polymerase activities present in the DNA-bindung proteins of normal human dermis, epidermis, horny layer …

1978

DNA-binding proteins (DBP) of normal human dermis, epidermis, horny layer and psoriatic scales represent a tissue-specific group of mostly nuclear nonhistone proteins. To analyse their function, the different DBP fractions were examined concerning the presence of DNase, DNA-polymerase and RNA-polymerase activities. DBP of normal epidermis and horny layer contain four different DNases. One DNase of both DBP fractions is active only at pH 5.0. Three DNases of epidermal DBP are active at a pH-range from 5.0--8.5, while the corresponding DNases of horny layer-DBP are most active at pH 7.4. Probably these DNases have changed their pH-optimum during keratinisation. DBP of psoriatic scales include…

Mutations in CTC1, encoding conserved telomere maintenance component 1, cause Coats plus

2012

Coats plus is a highly pleiotropic disorder particularly affecting the eye, brain, bone and gastrointestinal tract. Here, we show that Coats plus results from mutations in CTC1, encoding conserved telomere maintenance component 1, a member of the mammalian homolog of the yeast heterotrimeric CST telomeric capping complex. Consistent with the observation of shortened telomeres in an Arabidopsis CTC1 mutant and the phenotypic overlap of Coats plus with the telomeric maintenance disorders comprising dyskeratosis congenita, we observed shortened telomeres in three individuals with Coats plus and an increase in spontaneous γ 3H2AX-positive cells in cell lines derived from two affected individual…

Cloning, deletion, and characterization of PadR, the transcriptional repressor of the phenolic acid decarboxylase-encoding padA gene of Lactobacillus…

2004

ABSTRACTLactobacillus plantarumdisplays a substrate-induciblepadAgene encoding a phenolic acid decarboxylase enzyme (PadA) that is considered a specific chemical stress response to the inducing substrate. The putative regulator ofpadAwas located in thepadAlocus based on its 52% identity with PadR, thepadAgene transcriptional regulator ofPediococcus pentosaceus(L. Barthelmebs, B. Lecomte, C. Diviès, and J.-F. Cavin, J. Bacteriol.182:6724-6731, 2000). Deletion of theL. plantarum padRgene clearly demonstrates that the protein it encodes is the transcriptional repressor of divergently orientedpadA. ThepadRgene is cotranscribed with a downstream open reading frame (ORF1), the product of which m…

Efficient Control of raf Gene Expression by CAP and Two Raf Repressors that Bend DNA in Opposite Directions

1999

The plasmid-borne raf operon of Escherichia coli encodes proteins involved in the uptake and utilisation of the trisaccharide raffinose. The operon is subject to dual regulation; to negative control by the binding of RafR repressor to twin operators, O1 and O2, and to positive control by the cAMP-binding protein, CAP. We have identified the CAP binding site (CBS) as a 22 bp palindromic sequence with incomplete dyad symmetry by deletion analysis, DNasel footprinting and electrophoretic mobility shift assays (EMSA) of CAP-DNA complexes. The CBS is centred 60.5 bp upstream of the transcription start point and partially overlaps O1. In vivo, CAP increases rafA (alpha-galactosidase) gene express…

Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significa…

2000

The expression of the nuoA-N operon of Escherichia coli K-12, which encodes the proton-pumping NADH dehydrogenase I is modulated by growth phase-dependent regulation. Under respiratory growth conditions, expression was stimulated in early exponential, and to a lesser extent in late exponential and stationary growth phases. The stimulation in the early exponential growth phase was not observed in fis mutants, which are deficient for the growth phase-responsive regulator Fis. Neither the alternative sigma factor RpoS nor the integration host factor (IHF) are involved in growth phase-dependent regulation of this operon. When incubated with nuo promoter DNA, isolated Fis protein formed three re…

Requirement of the Lactobacillus casei MaeKR two-component system for L-malic acid utilization via a malic enzyme pathway.

2009

ABSTRACTLactobacillus caseican metabolizel-malic acid via malolactic enzyme (malolactic fermentation [MLF]) or malic enzyme (ME). Whereas utilization ofl-malic acid via MLF does not support growth, the ME pathway enablesL. caseito grow onl-malic acid. In this work, we have identified in the genomes ofL. caseistrains BL23 and ATCC 334 a cluster consisting of two diverging operons,maePEandmaeKR, encoding a putative malate transporter (maeP), an ME (maeE), and a two-component (TC) system belonging to the citrate family (maeKandmaeR). Homologous clusters were identified inEnterococcus faecalis,Streptococcus agalactiae,Streptococcus pyogenes, andStreptococcus uberis. Our results show that ME is …

Role of two operators in regulating the plasmid-borne raf operon of Escherichia coli

1994

The plasmid-borne raf operon encodes functions required for the inducible uptake and utilization of raffinose in Escherichia coli K12. The expression of three structural genes for alpha-galactosidase (rafA), Raf permease (rafB) and sucrose hydrolase (rafD) is negatively controlled by the binding of RafR repressor (rafR) to two operator sites, O1 and O2, that flank the -35 sequence of the raf promoter, PA. In vitro, O1 and O2 are occupied on increasing the concentration of RafR, without detectable preference for one site or the other or any indication of cooperative binding. Nucleotide substitutions at positions 3, 4 or 5 in an operator half-site prevented repressor binding, supporting a mod…

Prephenate dehydratase from the aphid endosymbiont (Buchnera) displays changes in the regulatory domain that suggest its desensitization to inhibitio…

2000

ABSTRACT Buchnera aphidicola , the prokaryotic endosymbiont of aphids, complements dietary deficiencies with the synthesis and provision of several essential amino acids. We have cloned and sequenced a region of the genome of B. aphidicola isolated from Acyrthosiphon pisum which includes the two-domain aroQ/pheA gene. This gene encodes the bifunctional chorismate mutase-prephenate dehydratase protein, which plays a central role in l -phenylalanine biosynthesis. Two changes involved in the overproduction of this amino acid have been detected. First, the absence of an attenuator region suggests a constitutive expression of this gene. Second, the regulatory domain of the Buchnera prephenate de…

Multiple Site-Specific Binding of Fis Protein to Escherichia coli nuoA-N Promoter DNA and its Impact on DNA Topology Visualised by Means of Scanning …

2004

Influence of molecular weight of DNA on the determination of anti-DNA antibodies in systemic lupus erythematosus (SLE) sera by radioimmunoassay

1975

Using a radioimmunoassay (RIA) based on the Farr technique with radioactively labeled 3-H-DNA for quantitative measurements of anti-DNA antibodies in sera of patients with systemic lupus erythematosus (SLE), the influence of molecular weight of DNA (ranging from 0.1 times 10-6 to 22.0 times 10-6 daltons) on binding and precipitation in this system has been investigated. Comparing our results with mathematical models it follows that one antibody molecule is fixed on the average to a statistical DNA segment of 2 times 10-6 to 4 times 10-6 daltons. Furthermore binding capacity of the DNA was found to be independent of the molecular weight, as demonstrated in a double label experiment using 14-…