Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of Tn917lac insertions define the comG region of the Bacillus subtilis chromosome. comG mutants are deficient in competence and specifically in the binding of exogenous DNA. The genes included in the comG region are first expressed during the transition from the exponential to the stationary growth phase. From nucleotide sequence information, it was concluded that the comG locus contains seven open reading frames (ORFs), several of which overlap at their termini. High-resolution S1 nuclease mapping and primer extension were used to identify the 5' terminus of the comG mRNA. The sequence upstream from the comG start site closely resembled the consensus recognition sequence for the major B. subtilis vegetative RNA polymerase holoenzyme. Complementation analysis confirmed that the comG ORF1 protein is required for the ability of competent cultures to resolve into two populations with different cell densities on Renografin (E. R. Squibb & Sons, Princeton, N.J.) gradients, as well as for full expression of comE, another late competence locus. The predicted comG ORF1 protein showed significant similarity to the virB ORF11 protein from Agrobacterium tumefaciens, which is probably involved in T-DNA transfer. The N-terminal sequences of comG ORF3 and, to a lesser extent, the comG ORF4 and ORF5 proteins were similar to a class of pilin proteins from members of the genera Bacteroides, Pseudomonas, Neisseria, and Moraxella. All of the comG proteins except comG ORF1 possessed hydrophobic domains that were potentially capable of spanning the bacterial membrane. It is likely that these proteins are membrane associated, and they may comprise part of the DNA transport machinery. When present in multiple copies, a DNA fragment carrying the comG promoter was capable of inhibiting the development of competence as well as the expression of several late com genes, suggesting a role for a transcriptional activator in the expression of those genes.
...
PMID:Nucleotide sequence and genetic organization of the Bacillus subtilis comG operon. 250 24

Fusion proteins known to activate transcription in vivo were tested for the ability to stimulate transcription in vitro in a recently developed Saccharomyces cerevisiae RNA polymerase II transcription system. One fusion protein, whose activation domain was derived from the herpesvirus transcriptional activator VP16, gave more than 100-fold stimulation in the in vitro system. The order of effects of the various proteins was the same for transcription in vitro and in vivo, suggesting that the natural mechanism of activation is preserved in vitro.
...
PMID:Activation of yeast polymerase II transcription by herpesvirus VP16 and GAL4 derivatives in vitro. 255 40

Citrobacter freundii encodes an inducible chromosomal beta-lactamase. Induction requires the product of the ampR gene, which is transcribed in the opposite orientation from the ampC beta-lactamase gene. We show here that the AmpR protein acts as a transcriptional activator by binding to a DNA region immediately upstream of the ampC promoter. The DNase I footprint pattern was not affected by growth in the presence of beta-lactam inducer or by the use of extracts prepared from cells carrying the ampD2 allele leading to semiconstitutive production of beta-lactamase. It is suggested that activation of AmpR facilitates binding or open complex formation for RNA polymerase at the ampC promoter. The AmpR-binding site overlaps the ampR promoter, and beta-galactosidase activity was decreased from an ampR-lacZ transcriptional fusion when AmpR was expressed from a coresident plasmid, suggesting that ampR is autogenously controlled. The AmpR protein belongs to a family of highly homologous transcriptional activators that includes LysR, which regulates the E. coli lysine synthetase gene, and the NodD protein, which regulates expression of a number of genes involved in nodulation in Rhizobium. The lack of sequence homology to any known beta-lactam-binding protein suggests that AmpR does not bind directly to the beta-lactam inducer but interacts with a second messenger of unknown nature.
...
PMID:Binding of the Citrobacter freundii AmpR regulator to a single DNA site provides both autoregulation and activation of the inducible ampC beta-lactamase gene. 278 68

According to our present understanding, lambda repressor bound to DNA stimulates transcription by touching RNA polymerase bound at an adjacent promoter. The part of repressor required for activation was identified in part by the isolation of mutants specifically impaired in transcriptional activation. The amino acids of repressor altered in these "positive control" mutants lie in an acidic patch on the surface of repressor that is closely apposed to RNA polymerase. In this study, we show that this "activating patch" of repressor is sufficient for transcriptional activation in another sequence context. We transfer this activating patch onto the surface of lambda Cro, a protein normally unable to activate transcription, and show that the modified Cro is a transcriptional activator. In addition, we provide evidence that the repressor protein of phage 434 also activates transcription using an activating patch similar to that of lambda repressor.
...
PMID:Turning lambda Cro into a transcriptional activator. 296 42

The E. coli ada gene positively controls its own expression and that of other genes (alkA, alkB, aidB) involved in repair of DNA alkylation damage. The cloned ada and alkA genes and purified Ada protein have been used in cell-free systems to identify the inducing signal. Self-methylation of the Ada protein by transfer of a methyl group from a phosphotriester in alkylated DNA to a cysteine residue in the protein converts it to an activator of transcription. The covalently modified Ada protein binds specifically to promoter regions containing the sequence d(AAANNAAAGCGCA) immediately upstream of the RNA polymerase binding sites. This is apparently the first example of conversion of a regulatory gene product to a transcriptional activator by a posttranslational modification event.
...
PMID:The intracellular signal for induction of resistance to alkylating agents in E. coli. 300 22

As a transcriptional activator, the N protein of phage lambda acts to suppress transcription termination by recognizing a promoter-proximal site, nut, which is separated from the terminators by thousands of base pairs. We demonstrate here that N interacts with the elongating RNA polymerase in transit through the boxB domain of nut. This interaction leads to the stable association of N as an integral component of the transcription apparatus. During subsequent elongation, N translocates along with polymerase through several defined terminators positioned beyond nut. Therefore, by being an operon-specific subunit of the transcription apparatus, N presumably prevents the interaction of polymerase with termination signals.
...
PMID:An antitermination protein engages the elongating transcription apparatus at a promoter-proximal recognition site. 304 Feb 63

GAL4 is a transcriptional activator found in yeast. Two distinct functions of the protein are required for its activity: one directs sequence-specific DNA binding, and another interacts with some other component of the transcriptional machinery, for example, RNA polymerase II or a TATA-binding protein. Two short regions of GAL4 function as 'activating sequences' when attached to the DNA-binding portion of GAL4 and these regions can be replaced by a large number of peptides encoded by Escherichia coli genomic DNA fragments or by a synthetic peptide designed to form an amphiphilic alpha-helix. All of these activating sequences, like that found in another yeast activator, GCN4 bear an excess negative charge. GAL4 and its derivatives that are active in yeast stimulate transcription in mammalian cells when GAL4 binding sites are introduced upstream of a mammalian gene; similarly, GAL4 activates transcription in Drosophila cells. Here we show that GAL4 derivatives stimulate gene expression in plant cells.
...
PMID:Yeast activators stimulate plant gene expression. 316 94

We have determined the nucleotide sequence of the xylR gene for a transcriptional activator for the degradative pathway of aromatic hydrocarbons on the TOL plasmid from Pseudomonas putida. The 1698-bp sequence for a 566-amino acid (aa) protein (Mr 63741) was identified as the XylR-encoding sequence. Three regions in XylR show homology to Klebsiella pneumoniae NtrC and NifA, both of which are transcriptional activators for the ntr and nif genes involved in the nitrogen metabolism. The central region of XylR (aa 234-473) corresponds to the region that was proposed to interact with RNA polymerase having a sigma factor, NtrA [Drummond et al., EMBO J. 5 (1986) 441-447]. The C-terminal region (aa 515-558) has a putative DNA-binding structure. A short segment proximal to the central region (aa 211-229) is thought to be an interdomain linker. No amino acid homology was found in the N-terminal regions among these proteins. These findings suggest the interaction of XylR with an NtrA in the transcriptional activation of the degradative pathway.
...
PMID:Nucleotide sequence of the regulatory gene xylR of the TOL plasmid from Pseudomonas putida. 316 74

The initiation of transcription from the nitrogen-regulated promoter glnAp2 requires RNA polymerase containing sigma 54, the transcriptional activator NRI, and the protein kinase NRII, responsible for the conversion of NRI to the active NRI-phosphate. NRI-phosphate does not increase the ability of sigma 54-containing RNA polymerase to bind to the promoter, but rather stimulates the conversion of an initial promoter:polymerase complex to the transcriptionally active open complex. The presence on the DNA template of high-affinity binding sites for NRI/NRI-phosphate, normally located 130 and 100 bp upstream of the site of transcription initiation, results in a 4- to 5-fold lowering of the concentration of NRI required for the formation of the open complex. These high-affinity NRI binding sites facilitate open complex formation when they are moved to positions 700 bp further upstream or 950 bp downstream of glnAp2 on linear DNA templates.
...
PMID:Initiation of transcription at the bacterial glnAp2 promoter by purified E. coli components is facilitated by enhancers. 330 60

Expression of the Escherichia coli maltose regulon is controlled by MalT, a transcriptional activator (Mr = 102,288) encoded by the malT gene. Activation of transcription depends on the presence of the inducer, maltotriose. Using an in vitro transcription/translation assay to monitor the protein, we have purified MalT in native form from MalT-overproducing bacteria. The purified protein is able to promote transcription from different MalT-controlled promoters in well-defined in vitro systems. Maltotriose and the MalT protein suffice to stimulate initiation of transcription at malPp by the E. coli RNA polymerase holoenzyme. In contrast, both MalT protein and cAMP receptor protein are required with their respective effectors, maltotriose and cyclic AMP, for activation of malEp. These data are in agreement with in vivo observations. In addition, we present evidence that MalT is an ATP-binding protein, a result suggesting that ATP may play a role in transcription initiation.
...
PMID:Purification and properties of the MalT protein, the transcription activator of the Escherichia coli maltose regulon. 330 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---