scholarly journals Forespore-Specific Expression of Bacillus subtilis yqfS, Which Encodes Type IV Apurinic/Apyrimidinic Endonuclease, a Component of the Base Excision Repair Pathway

2003 ◽  
Vol 185 (1) ◽  
pp. 340-348 ◽  
Author(s):  
Norma Urtiz-Estrada ◽  
José M. Salas-Pacheco ◽  
Ronald E. Yasbin ◽  
Mario Pedraza-Reyes
Keyword(s):  
Bacillus Subtilis ◽  
Excision Repair ◽  
Transcriptional Start Site ◽  
Northern Blotting ◽  
Start Codon ◽  
Start Site ◽  
Specific Expression ◽  
Reading Frame ◽  
Type Iv

ABSTRACT The temporal and spatial expression of the yqfS gene of Bacillus subtilis, which encodes a type IV apurinic/apyrimidinic endonuclease, was studied. A reporter gene fusion to the yqfS opening reading frame revealed that this gene is not transcribed during vegetative growth but is transcribed during the last steps of the sporulation process and is localized to the developing forespore compartment. In agreement with these results, yqfS mRNAs were mainly detected by both Northern blotting and reverse transcription-PCR, during the last steps of sporulation. The expression pattern of the yqfS-lacZ fusion suggested that yqfS may be an additional member of the EσG regulon. A primer extension product mapped the transcriptional start site of yqfS, 54 to 55 bp upstream of translation start codon of yqfS. Such an extension product was obtained from RNA samples of sporulating cells but not from those of vegetatively growing cells. Inspection of the nucleotide sequence lying upstream of the in vivo-mapped transcriptional yqfS start site revealed the presence of a sequence with good homology to promoters preceding genes of the σG regulon. Although yqfS expression was temporally regulated, neither oxidative damage (after either treatment with paraquat or hydrogen peroxide) nor mitomycin C treatment induced the transcription of this gene.

scholarly journals Regulation of the furA and catC Operon, Encoding a Ferric Uptake Regulator Homologue and Catalase-Peroxidase, Respectively, in Streptomyces coelicolor A3(2)

2000 ◽  
Vol 182 (13) ◽  
pp. 3767-3774 ◽  
Author(s):  
Ji-Sook Hahn ◽  
So-Young Oh ◽  
Jung-Hye Roe
Keyword(s):  
Streptomyces Coelicolor ◽  
Transcriptional Start Site ◽  
Protein Product ◽  
Negative Regulator ◽  
Start Codon ◽  
Multicopy Plasmid ◽  
Ferric Uptake Regulator ◽  
Start Site ◽  
Reading Frame ◽  
Catalase Peroxidase

ABSTRACT We isolated the catC gene, encoding catalase-peroxidase in Streptomyces coelicolor, using sequence homology with the katG gene from Escherichia coli. Upstream of the catC gene, an open reading frame (furA) encoding a homologue of ferric uptake regulator (Fur) was identified. S1 mapping analysis indicated that the furA gene was cotranscribed with the catC gene. The transcriptional start site of the furA-catC mRNA was mapped to the translation start codon ATG of the furA gene. The putative promoter contains consensus −10 and −35 elements similar to those recognized by ςHrdB, the major sigma factor of S. coelicolor. The transcripts were produced maximally at late-exponential phase and decreased at the stationary phase in liquid culture. The change in the amount of mRNA was consistent with that of CatC protein and enzyme activity. When the furA gene was introduced into S. lividans on a multicopy plasmid, the increased production of catC transcripts and protein product at late growth phase was inhibited, implying a role for FurA as the negative regulator of the furA-catC operon. FurA protein bound to its own promoter region between −59 and −39 nucleotides from the transcription start site. The binding affinity of FurA increased under reducing conditions and in the presence of metals such as Ni2+, Mn2+, Zn2+, or Fe2+. Addition of these metals to the growth medium decreased the production of CatC protein, consistent with the role of FurA as a metal-dependent repressor.

scholarly journals Transcriptional Analysis and Regulation of Expression of the ScrFI Restriction-Modification System of Lactococcus lactis subsp.cremoris UC503

2001 ◽  
Vol 183 (15) ◽  
pp. 4668-4673 ◽  
Author(s):  
Derek Butler ◽  
Gerald F. Fitzgerald
Keyword(s):  
Transcriptional Start Site ◽  
Transcriptional Analysis ◽  
Start Codon ◽  
Northern Analysis ◽  
Start Site ◽  
Regulation Of Expression ◽  
Modification System ◽  
Reading Frame ◽  
Restriction Modification System ◽  
Restriction Modification

ABSTRACT ScrFI is a type II restriction-modification system from Lactococcus lactis which recognizes the nucleotide sequence 5′-CC↓ NGG-3′, cleaving at the point indicated by the arrow, and it comprises an endonuclease gene that is flanked on either side by genes encoding two 5-methylcytosine methylases. An open reading frame (orfX) of unknown function is located immediately upstream of these genes. In this study Northern analysis was performed, and it revealed that orfX, scrFIBM, andscrFIR are cotranscribed as a single polygenic mRNA molecule, while scrFIAM is transcribed independently. 5′ extension analysis indicated that the start site for thescrFIAM promoter was a thymine located 4 bp downstream of the −10 motif. The transcriptional start site for theorfX promoter was also found to be a thymine which is more atypically located 24 bp downstream of the −10 motif proximal to the start codon. A helix-turn-helix motif was identified at the N-terminal end of one of the methylases (M.ScrFIA). In order to determine if this motif played a role in regulation of the ScrFI locus, M.ScrFIA was purified. It was then employed in gel retardation assays using fragments containing the two promoters found on the ScrFI operon, one located upstream oforfX and the other located just upstream ofscrFIAM. M.ScrFIA was found to bind to the promoter region upstream of the gene encoding it, indicating that it may have a regulatory role. In further studies the two putative promoters were introduced into a vector (pAK80) upstream of a promoterless lacZ gene, and cloned fragments of theScrFI locus were introduced in trans with each of these promoter constructs to investigate the effect on promoter activity. These results implicated M.ScrFIA in regulation of both promoters on the ScrFI locus.

scholarly journals Poly-3-Hydroxybutyrate Degradation in Rhizobium (Sinorhizobium) meliloti: Isolation and Characterization of a Gene Encoding 3-Hydroxybutyrate Dehydrogenase

1999 ◽  
Vol 181 (3) ◽  
pp. 849-857 ◽  
Author(s):  
P. Aneja ◽  
T. C. Charles
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Sinorhizobium Meliloti ◽  
Transcriptional Start Site ◽  
Consensus Sequence ◽  
Start Codon ◽  
Start Site ◽  
Gene Encoding ◽  
Reading Frame ◽  
Isolation And Characterization

ABSTRACT We have cloned and sequenced the 3-hydroxybutyrate dehydrogenase-encoding gene (bdhA) from Rhizobium (Sinorhizobium) meliloti. The gene has an open reading frame of 777 bp that encodes a polypeptide of 258 amino acid residues (molecular weight 27,177, pI 6.07). The R. meliloti Bdh protein exhibits features common to members of the short-chain alcohol dehydrogenase superfamily. bdhA is the first gene transcribed in an operon that also includes xdhA, encoding xanthine oxidase/dehydrogenase. Transcriptional start site analysis by primer extension identified two transcription starts. S1, a minor start site, was located 46 to 47 nucleotides upstream of the predicted ATG start codon, while S2, the major start site, was mapped 148 nucleotides from the start codon. Analysis of the sequence immediately upstream of either S1 or S2 failed to reveal the presence of any known consensus promoter sequences. Although a ς54 consensus sequence was identified in the region between S1 and S2, a corresponding transcript was not detected, and a rpoN mutant of R. meliloti was able to utilize 3-hydroxybutyrate as a sole carbon source. The R. meliloti bdhA gene is able to confer uponEscherichia coli the ability to utilize 3-hydroxybutyrate as a sole carbon source. An R. meliloti bdhA mutant accumulates poly-3-hydroxybutyrate to the same extent as the wild type and shows no symbiotic defects. Studies with a strain carrying alacZ transcriptional fusion to bdhAdemonstrated that gene expression is growth phase associated.

scholarly journals Regulation of Swarming Motility and flhDCSm Expression by RssAB Signaling in Serratia marcescens

2008 ◽  
Vol 190 (7) ◽  
pp. 2496-2504 ◽  
Author(s):  
Po-Chi Soo ◽  
Yu-Tze Horng ◽  
Jun-Rong Wei ◽  
Jwu-Ching Shu ◽  
Chia-Chen Lu ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Binding Site ◽  
Promoter Region ◽  
Transcriptional Start Site ◽  
Direct Interaction ◽  
Underlying Mechanism ◽  
Inhibitory Effect ◽  
Start Codon ◽  
Mobility Shift

ABSTRACT Serratia marcescens cells swarm at 30°C but not at 37°C, and the underlying mechanism is not characterized. Our previous studies had shown that a temperature upshift from 30 to 37°C reduced the expression levels of flhDCSm and hagSm in S. marcescens CH-1. Mutation in rssA or rssB, cognate genes that comprise a two-component system, also resulted in precocious swarming phenotypes at 37°C. To further characterize the underlying mechanism, in the present study, we report that expression of flhDCSm and synthesis of flagella are significantly increased in the rssA mutant strain at 37°C. Primer extension analysis for determination of the transcriptional start site(s) of flhDCSm revealed two transcriptional start sites, P1 and P2, in S. marcescens CH-1. Characterization of the phosphorylated RssB (RssB∼P) binding site by an electrophoretic mobility shift assay showed direct interaction of RssB∼P, but not unphosphorylated RssB [RssB(D51E)], with the P2 promoter region. A DNase I footprinting assay using a capillary electrophoresis approach further determined that the RssB∼P binding site is located between base pair positions −341 and −364 from the translation start codon ATG in the flhDCSm promoter region. The binding site overlaps with the P2 “−35” promoter region. A modified chromatin immunoprecipitation assay was subsequently performed to confirm that RssB∼P binds to the flhDCSm promoter region in vivo. In conclusion, our results indicated that activated RssA-RssB signaling directly inhibits flhDCSm promoter activity at 37°C. This inhibitory effect was comparatively alleviated at 30°C. This finding might explain, at least in part, the phenomenon of inhibition of S. marcescens swarming at 37°C.

The two isozymes of rat intestinal alkaline phosphatase are products of two distinct genes

2000 ◽  
Vol 3 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Q. XIE ◽  
D. H. ALPERS
Keyword(s):  
Alkaline Phosphatase ◽  
Transcriptional Start Site ◽  
In Vivo Studies ◽  
Peroxisome Proliferator ◽  
Start Site ◽  
Intestinal Alkaline Phosphatase ◽  
Promoter Regions ◽  
Flanking Regions

Xie, Q., and D. H. Alpers. The two isozymes of rat intestinal alkaline phosphatase are products of two distinct genes. Physiol Genomics 3: 1–8, 2000.—Rat intestinal alkaline phosphatases (IAP-I and -II) differ in primary structure, substrate specificity, tissue localization, and response to fat feeding. This study identifies two distinct genes (∼5–6 kb) corresponding to each isozyme and containing 11 exons of nearly identical size. The exon-intron junctions are identical with those found in IAP genes from other species. The 1.7 and 1.2 bp of 5′ flanking regions isolated from each gene, respectively, contain Sp1 and gut-enriched Kruppel-like factor (GKLF) binding sites, but otherwise show little identity. There is a potential CAAT-box 14 bp 5′ to the transcriptional start site, 36 bp upstream from IAP-I, and a TATA-box 31 bp 5′ to the transcriptional start site, 55 bp upstream from IAP-II. Transfection of these promoter regions (linked to luciferase as a reporter gene) into a kidney cell line, COS-7, produced the differential response to oleic acid expected from in vivo studies, i.e., threefold increase using the 5′ flanking region of IAP-II, but not IAP-I. This response was not reproduced by 5,8,11,14-eicosatetraynoic acid (ETYA) or clofibrate, suggesting that peroxisome proliferator response elements are not involved. Isolation of the IAP-II gene will allow determination of the sequences responsible for dietary fat response in the enterocyte.

scholarly journals Characterization of PmfR, the Transcriptional Activator of the pAO1-Borne purU-mabO-folD Operon of Arthrobacter nicotinovorans

2005 ◽  
Vol 187 (9) ◽  
pp. 3062-3070 ◽  
Author(s):  
Calin B. Chiribau ◽  
Cristinel Sandu ◽  
Gabor L. Igloi ◽  
Roderich Brandsch
Keyword(s):  
Binding Site ◽  
Transcriptional Start Site ◽  
Transcriptional Activator ◽  
Open Reading Frames ◽  
Start Site ◽  
Gene Encoding ◽  
Chloramphenicol Resistance ◽  
Nuclease Digestion ◽  
Arthrobacter Nicotinovorans

ABSTRACT Nicotine catabolism by Arthrobacter nicotinovorans is linked to the presence of the megaplasmid pAO1. Genes involved in this catabolic pathway are arranged on the plasmid into gene modules according to function. During nicotine degradation γ-N-methylaminobutyrate is formed from the pyrrolidine ring of nicotine. Analysis of the pAO1 open reading frames (ORF) resulted in identification of the gene encoding a demethylating γ-N-methylaminobutyrate oxidase (mabO). This gene was shown to form an operon with purU- and folD-like genes. Only in bacteria grown in the presence of nicotine could transcripts of the purU-mabO-folD operon be detected, demonstrating that this operon constitutes part of the pAO1 nicotine regulon. Its transcriptional start site was determined by primer extension analysis. Transcription of the operon was shown to be controlled by a new transcriptional regulator, PmfR, the product of a gene that is transcribed divergently from the purU, mabO, and folD genes. PmfR was purified, and electromobility shift assays and DNase I-nuclease digestion experiments were used to determine that its DNA binding site is located between −48 and −88 nucleotides upstream of the transcriptional start site of the operon. Disruption of pmfR by homologous recombination with a chloramphenicol resistance cassette demonstrated that PmfR acts in vivo as a transcriptional activator. Mutagenesis of the PmfR target DNA suggested that the sequence GTTT-14 bp-AAAC is the core binding site of the regulator upstream of the −35 promoter region of the purU-mabO-folD operon.

Molecular characterization of a developmentally regulated porcine skeletal myosin heavy chain gene and its 5′ regulatory region

1995 ◽  
Vol 108 (4) ◽  
pp. 1779-1789 ◽  
Author(s):  
K.C. Chang ◽  
K. Fernandes ◽  
M.J. Dauncey
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Transcriptional Start Site ◽  
Regulatory Region ◽  
Chain Gene ◽  
Specific Expression ◽  
Slow Fibre ◽  
Skeletal Myosin

Members of the myosin heavy chain (MyHC) gene family show developmental stage- and spatial-specificity of expression. We report on the characterization and identification of a porcine skeletal fast MyHC gene, including its corresponding 5′ end cDNA and 5′ regulatory region. This MyHC isoform was found exclusively in skeletal muscles from about the last quarter of gestation through to adulthood. Expression of this isoform was higher postnatally and its spatial distribution resembled a rosette cluster; each with a ring of fast fibres surrounding a central slow fibre. This rosette pattern was absent in the adult diaphragm but about 20% of the fibres continued to express this MyHC isoform. Further in vivo expression studies, in a variety of morphologically and functionally diverse muscles, showed that this particular skeletal MyHC isoform was expressed in fast oxidative-glycolytic fibres, suggesting that it was the equivalent of the fast IIA isoform. Two domains in the upstream regulatory region were found to confer differentiation-specific expression on C2 myotubes (−1007 to -828 and -455 to -101), based on in vitro transient expression assays using the chloramphenicol acetyltransferase (CAT) reporter gene. Interestingly, for high levels of CAT expression to occur, a 3′ region, extending from the transcriptional start site to part. of intron 2, must be present in all the DNA constructs used.

scholarly journals The Mof2/Sui1 Protein Is a General Monitor of Translational Accuracy

1998 ◽  
Vol 18 (3) ◽  
pp. 1506-1516 ◽  
Author(s):  
Ying Cui ◽  
Jonathan D. Dinman ◽  
Terri Goss Kinzy ◽  
Stuart W. Peltz
Keyword(s):  
Site Selection ◽  
Start Site ◽  
Wild Type ◽  
Virus Propagation ◽  
Ribosomal Frameshifting ◽  
Reading Frame ◽  
Translational Accuracy ◽  
Its Gene ◽  
Killer Virus

ABSTRACT Although it is essential for protein synthesis to be highly accurate, a number of cases of directed ribosomal frameshifting have been reported in RNA viruses, as well as in procaryotic and eucaryotic genes. Changes in the efficiency of ribosomal frameshifting can have major effects on the ability of cells to propagate viruses which use this mechanism. Furthermore, studies of this process can illuminate the mechanisms involved in the maintenance of the normal translation reading frame. The yeast Saccharomyces cerevisiae killer virus system uses programmed −1 ribosomal frameshifting to synthesize its gene products. Strains harboring the mof2-1 allele demonstrated a fivefold increase in frameshifting and prevented killer virus propagation. In this report, we present the results of the cloning and characterization of the wild-type MOF2 gene.mof2-1 is a novel allele of SUI1, a gene previously shown to play a role in translation initiation start site selection. Strains harboring the mof2-1 allele demonstrated a mutant start site selection phenotype and increased efficiency of programmed −1 ribosomal frameshifting and conferred paromomycin sensitivity. The increased frameshifting observed in vivo was reproduced in extracts prepared from mof2-1 cells. Addition of purified wild-type Mof2p/Sui1p reduced frameshifting efficiencies to wild-type levels. Expression of the human SUI1 homolog in yeast corrects all of the mof2-1 phenotypes, demonstrating that the function of this protein is conserved throughout evolution. Taken together, these results suggest that Mof2p/Sui1p functions as a general modulator of accuracy at both the initiation and elongation phases of translation.

scholarly journals Regulation of Expression of the adhE Gene, Encoding Ethanol Oxidoreductase in Escherichia coli: Transcription from a Downstream Promoter and Regulation by Fnr and RpoS

1999 ◽  
Vol 181 (24) ◽  
pp. 7571-7579 ◽  
Author(s):  
Jorge Membrillo-Hernández ◽  
E. C. C. Lin
Keyword(s):  
Escherichia Coli ◽  
Transcriptional Start Site ◽  
Start Codon ◽  
Start Site ◽  
Rnase Iii ◽  
Regulation Of Expression ◽  
Experimental Conditions ◽  
Stem Loop ◽  
Translational Start ◽  
Transcriptional Start Sites

ABSTRACT The adhE gene of Escherichia coli, located at min 27 on the chromosome, encodes the bifunctional NAD-linked oxidoreductase responsible for the conversion of acetyl-coenzyme A to ethanol during fermentative growth. The expression of adhEis dependent on both transcriptional and posttranscriptional controls and is about 10-fold higher during anaerobic than during aerobic growth. Two putative transcriptional start sites have been reported: one at position −292 and the other at −188 from the translational start codon ATG. In this study we show, by using several different transcriptional and translational fusions to the lacZ gene, that both putative transcriptional start sites can be functional and each site can be redox regulated. Although both start sites are NarL repressible in the presence of nitrate, Fnr activates only the −188 start site and Fis is required for the transcription of only the −292 start site. In addition, it was discovered that RpoS activatesadhE transcription at both start sites. Under all experimental conditions tested, however, only the upstream start site is active. Available evidence indicates that under those conditions, the upstream promoter region acts as a silencer of the downstream transcriptional start site. Translation of the mRNA starting at −292, but not the one starting at −188, requires RNase III. The results support the previously postulated ribosomal binding site (RBS) occlusion model, according to which RNase III cleavage is required to release the RBS from a stem-loop structure in the long transcript.

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