scholarly journals Characterization of devH, a Gene Encoding a Putative DNA Binding Protein Required for Heterocyst Function inAnabaena sp. Strain PCC 7120

2000 ◽  
Vol 182 (12) ◽  
pp. 3572-3581 ◽  
Author(s):  
Pratibha B. Hebbar ◽  
Stephanie E. Curtis
Keyword(s):  
Dna Binding ◽  
Time Course ◽  
Nitrogen Starvation ◽  
Receptor Protein ◽  
Fixed Nitrogen ◽  
Gene Encoding ◽  
Reading Frame ◽  
Pcc 7120

ABSTRACT The devH gene was identified in a screen forAnabaena sp. strain PCC 7120 sequences whose transcripts increase in abundance during a heterocyst development time course. The product of devH contains a helix-turn-helix motif similar to the DNA binding domain of members of the cyclic AMP receptor protein family, and the protein is most closely related to the cyanobacterial transcriptional activator NtcA. devH transcripts are barely detectable in vegetative cells and are induced approximately fivefold after nitrogen starvation. This induction is absent in the two developmental mutants hetR and ntcA. The gene is expressed as monocistronic transcripts with multiple 5′ termini, and the ∼500-bp region 5′ to devH was shown to have promoter activity in vivo. The devH gene was insertionally inactivated by the integration of plasmid sequences within the open reading frame. Nitrogen starvation of the devH mutant induces heterocysts of wild-type morphology, but the mutant is inviable in the absence of fixed nitrogen and unable to reduce acetylene aerobically.

scholarly journals τ91, an Essential Subunit of Yeast Transcription Factor IIIC, Cooperates with τ138 in DNA Binding

1998 ◽  
Vol 18 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Rosalía Arrebola ◽  
Nathalie Manaud ◽  
Sophie Rozenfeld ◽  
Marie-Claude Marsolier ◽  
Olivier Lefebvre ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Essential Gene ◽  
Open Reading Frames ◽  
Class Iii ◽  
Gene Encoding ◽  
Promoter Recognition

ABSTRACT Transcription factor IIIC (TFIIIC) (or τ) is a large multisubunit and multifunctional factor required for transcription of all class III genes in Saccharomyces cerevisiae. It is responsible for promoter recognition and TFIIIB assembly. We report here the cloning and characterization of TFC6, an essential gene encoding the 91-kDa polypeptide, τ91, present in affinity-purified TFIIIC. τ91 has a predicted molecular mass of 74 kDa. It harbors a central cluster of His and Cys residues and has basic and acidic amino acid regions, but it shows no specific similarity to known proteins or predicted open reading frames. The TFIIIC subunit status of τ91 was established by the following biochemical and genetic evidence. Antibodies to τ91 bound TFIIIC-DNA complexes in gel shift assays; in vivo, a B block-deficient U6 RNA gene (SNR6) harboring GAL4 binding sites was reactivated by fusing the GAL4 DNA binding domain to τ91; and a point mutation in TFC6 (τ91-E330K) was found to suppress the thermosensitive phenotype of a tfc3-G349Emutant affected in the B block binding subunit (τ138). The suppressor mutation alleviated the DNA binding and transcription defects of mutant TFIIIC in vitro. These results indicated that τ91 cooperates with τ138 for DNA binding. Recombinant τ91 by itself did not interact with a tRNA gene, although it showed a strong affinity for single-stranded DNA.

scholarly journals The EIIGlc Protein Is Involved in Glucose-Mediated Activation of Escherichia coli gapA andgapB-pgk Transcription

1998 ◽  
Vol 180 (24) ◽  
pp. 6476-6483 ◽  
Author(s):  
B. Charpentier ◽  
V. Bardey ◽  
N. Robas ◽  
C. Branlant
Keyword(s):  
Escherichia Coli ◽  
Binding Site ◽  
Promoter Activity ◽  
Protein A ◽  
Phosphoglycerate Kinase ◽  
Receptor Protein ◽  
Mrna Levels ◽  
Gene Encoding ◽  
Reading Frame

ABSTRACT The Escherichia coli gapB gene codes for a protein that is very similar to bacterial glyceraldehyde-3-phosphate dehydrogenases (GAPDH). In most bacteria, the gene for GAPDH is located upstream of the pgk gene encoding 3-phosphoglycerate kinase (PGK). This is the case for gapB. However, this gene is poorly expressed and encodes a protein with an erythrose 4-phosphate dehydrogenase activity (E4PDH). The active GAPDH is encoded by thegapA gene. Since we found that the nucleotide region upstream of the gapB open reading frame is responsible for part of the PGK production, we analyzed gapB promoter activity in vivo by direct measurement of the mRNA levels by reverse transcription. We showed the presence of a unique transcription promoter, gapB P0, with a cyclic AMP (cAMP) receptor protein (CRP)-cAMP binding site centered 70.5 bp upstream of the start site. Interestingly, the gapB P0 promoter activity was strongly enhanced when glucose was used as the carbon source. In these conditions, deletion of the CRP-cAMP binding site had little effect on promoter gapB P0 activity. In contrast, abolition of CRP production or of cAMP biosynthesis (crp or cyamutant strains) strongly reduced promoter gapB P0 activity. This suggests that in the presence of glucose, the CRP-cAMP complex has an indirect effect on promoter gapB P0 activity. We also showed that glucose stimulation of gapB P0 promoter activity depends on the expression of enzyme IIGlc(EIIGlc), encoded by the ptsG gene, and that the gapA P1 promoter is also activated by glucose via the EIIGlc protein. A similar glucose-mediated activation, dependent on the EIIGlc protein, was described by others for the pts operon. Altogether, this shows that when glucose is present in the growth medium expression of the E. coli genes required for its uptake (pts) and its metabolism (gapA and gapB-pgk) are coordinately activated by a mechanism dependent upon the EIIGlc protein.

scholarly journals Characterization of the Escherichia coli gene encoding a new member of the short-chain dehydrogenase/reductase (SDR) family.

1997 ◽  
Vol 44 (1) ◽  
pp. 153-157 ◽  
Author(s):  
A Sirko ◽  
A Wegleńska ◽  
M Hryniewicz ◽  
D M Hulanicka
Keyword(s):  
Escherichia Coli ◽  
Short Chain ◽  
Chromosomal Dna ◽  
Large Protein ◽  
Gene Encoding ◽  
Reading Frame ◽  
Large Protein Family ◽  
Dna Fragment

The nucleotide sequence of a chromosomal DNA fragment located upstream from the cysPTWAM operon of Escherichia coli was established. Sequence analysis indicates the presence of an open reading frame which has been designated ucpA (upstream cys P). The potential protein products exhibits strong sequence homology to the members of a large protein family, short-chain dehydrogenases/reductases. Involvement of Crp, FruR and IHF in the regulation of ucpA transcription in vivo was demonstrated.

scholarly journals Two related ARID family proteins are alternative subunits of human SWI/SNF complexes

2004 ◽  
Vol 383 (2) ◽  
pp. 319-325 ◽  
Author(s):  
Xiaomei WANG ◽  
Norman G. NAGL ◽  
Deborah WILSKER ◽  
Michael VAN SCOY ◽  
Stephen PACCHIONE ◽  
...  
Keyword(s):  
Dna Binding ◽  
Direct Evidence ◽  
Potential Interaction ◽  
Atpase Subunit ◽  
Reading Frame ◽  
Atpase Subunits ◽  
A Subunit ◽  
Distinct Subunit ◽  
Binding Behaviour

p270 (ARID1A) is a member of the ARID family of DNA-binding proteins and a subunit of human SWI/SNF-related complexes, which use the energy generated by an integral ATPase subunit to remodel chromatin. ARID1B is an independent gene product with an open reading frame that is more than 60% identical with p270. We have generated monoclonal antibodies specific for either p270 or ARID1B to facilitate the investigation of ARID1B and its potential interaction with human SWI/SNF complexes in vivo. Immunocomplex analysis provides direct evidence that endogenous ARID1B is associated with SWI/SNF-related complexes and indicates that p270 and ARID1B, similar to the ATPase subunits BRG1 and hBRM, are alternative, mutually exclusive subunits of the complexes. The ARID-containing subunits are not specific to the ATPases. Each associates with both BRG1 and hBRM, thus increasing the number of distinct subunit combinations known to be present in cells. Analysis of the panels of cell lines indicates that ARID1B, similar to p270, has a broad tissue distribution. The ratio of p270/ARID1B in typical cells is approx. 3.5:1, and BRG1 is distributed proportionally between the two ARID subunits. Analysis of DNA-binding behaviour indicates that ARID1B binds DNA in a non-sequence-specific manner similar to p270.

Biochemical and genetic characterization of a yeast TFIID mutant that alters transcription in vivo and DNA binding in vitro

1992 ◽  
Vol 12 (5) ◽  
pp. 2372-2382
Author(s):  
K M Arndt ◽  
S L Ricupero ◽  
D M Eisenmann ◽  
F Winston
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Direct Repeat ◽  
Single Amino Acid ◽  
Wild Type ◽  
Dna Binding Specificity ◽  
Selection For

A mutation in the gene that encodes Saccharomyces cerevisiae TFIID (SPT15), which was isolated in a selection for mutations that alter transcription in vivo, changes a single amino acid in a highly conserved region of the second direct repeat in TFIID. Among eight independent spt15 mutations, seven cause this same amino acid change, Leu-205 to Phe. The mutant TFIID protein (L205F) binds with greater affinity than that of wild-type TFIID to at least two nonconsensus TATA sites in vitro, showing that the mutant protein has altered DNA binding specificity. Site-directed mutations that change Leu-205 to five different amino acids cause five different phenotypes, demonstrating the importance of this amino acid in vivo. Virtually identical phenotypes were observed when the same amino acid changes were made at the analogous position, Leu-114, in the first repeat of TFIID. Analysis of these mutations and additional mutations in the most conserved regions of the repeats, in conjunction with our DNA binding results, suggests that these regions of the repeats play equivalent roles in TFIID function, possibly in TATA box recognition.

scholarly journals Cloning, Nucleotide Sequence, and Expression of the Gene Encoding the Bacteriocin Boticin B from Clostridium botulinum Strain 213B

2000 ◽  
Vol 66 (12) ◽  
pp. 5480-5483 ◽  
Author(s):  
Sean S. Dineen ◽  
Marite Bradshaw ◽  
Eric A. Johnson
Keyword(s):  
Amino Acids ◽  
Nucleotide Sequence ◽  
Clostridium Botulinum ◽  
Shuttle Vector ◽  
Open Reading Frame ◽  
Gene Encoding ◽  
Reading Frame ◽  
Heat Stable ◽  
Group I

ABSTRACT Boticin B is a heat-stable bacteriocin produced byClostridium botulinum strain 213B that has inhibitory activity against various strains of C. botulinum and related clostridia. The gene encoding the bacteriocin was localized to a 3.0-kb HindIII fragment of an 18.8-kb plasmid, cloned, and sequenced. DNA sequencing revealed the boticin B structural gene,btcB, to be an open reading frame encoding 50 amino acids. A C. botulinum strain 62A transconjugant containing theHindIII fragment inserted into a clostridial shuttle vector expressed boticin B, although at much lower levels than those observed in C. botulinum 213B. To our knowledge, this is the first demonstration and characterization of a bacteriocin from toxigenic group I C. botulinum.

scholarly journals Identification and Characterization of the PutP Proline Permease That Contributes to In Vivo Survival ofStaphylococcus aureus in Animal Models

1998 ◽  
Vol 66 (2) ◽  
pp. 567-572 ◽  
Author(s):  
William R. Schwan ◽  
Silvija N. Coulter ◽  
Eva Y. W. Ng ◽  
Michael H. Langhorne ◽  
Heather D. Ritchie ◽  
...  
Keyword(s):  
Animal Models ◽  
Reading Frame ◽  
High Affinity ◽  
Wound Model ◽  
Infection Models ◽  
Uptake Assay ◽  
Entire Open Reading Frame ◽  
In Vivo Growth

ABSTRACT Staphylococcus aureus is an important pathogen of humans and other animals, causing bacteremia, abscesses, endocarditis, and other infectious syndromes. A signature-tagged mutagenesis (STM) system was adapted for use in studying the genes required for in vivo survival of S. aureus. An STM library was ultimately created in S. aureus RN6390, with Tn917 being used to create the transposon mutations. Pools of S. aureusRN6390 mutants were screened in mouse abscess, bacteremia, and wound infection models for growth attenuation after in vivo passage. One of the mutants that was identified displayed marked attenuation following large-pool screening in all three animal models, which was confirmed in bacteremia and endocarditis models of infection with a smaller pool of mutants. Sequence analysis of the entire open reading frame showed a 99% identity to the high-affinity proline permease (putP) gene characterized in another strain of S. aureus. In wound and murine abscess infection models, the putP mutant was approximately 10-fold more attenuated than was wild-type strain RN6390. Another S. aureus strain transduced with theputP mutation also displayed an attenuated phenotype after passage in the wound model. A [3H]proline uptake assay showed that less proline was specifically transported into theputP mutant than into strain RN6390. The reduced viability of the bacteria possessing the mutation in the S. aureushigh-affinity proline permease suggests that proline scavenging by the bacteria is important for in vivo growth and proliferation and that analogs of proline may serve as potential antistaphylococcal therapeutic agents.

scholarly journals Characterization of quail Pax-6 (Pax-QNR) proteins expressed in the neuroretina.

1993 ◽  
Vol 13 (12) ◽  
pp. 7257-7266 ◽  
Author(s):  
C Carriere ◽  
S Plaza ◽  
P Martin ◽  
B Quatannens ◽  
M Bailly ◽  
...  
Keyword(s):  
Dna Binding ◽  
Autosomal Dominant ◽  
Paired Domain ◽  
Terminal Part ◽  
Dominant Mutation ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Carboxyl Terminal

After differential screening of a cDNA library constructed from quail neuroretina cells (QNR) infected with the v-myc-containing avian retrovirus MC29, we have isolated a cDNA clone, Pax-QNR, homologous to the murine Pax-6, which is mutated in the autosomal dominant mutation small eye of mice and in the disorder aniridia in humans. Here we report the characterization of the Pax-QNR proteins expressed in the avian neuroretina. From bacterially expressed Pax-QNR peptides, we obtained rabbit antisera directed against different domains of the protein: paired domain (serum 11), domain between the paired domain and homeodomain (serum 12), homeodomain (serum 13), and carboxyl-terminal part (serum 14). Sera 12, 13, and 14 were able to specifically recognize five proteins (48, 46, 43, 33, and 32 kDa) in the neuroretina. In contrast to proteins of 48, 46, and 43 kDa, proteins of 33 and 32 kDa were not recognized by the paired antiserum (serum 11). Paired-less and paired-containing proteins exhibited the same half-life (6 h) and were phosphorylated mostly on serine residues. Immunoprecipitations performed with subcellular fractions of neuroretinas showed that the paired-containing proteins were located in the nucleus, whereas the 33- and 32-kDa proteins were found essentially in the cytoplasmic compartment. However, immunofluorescence experiments performed after transient transfections showed that p46 and p33/32 were also located in vivo into the nucleus. Thus, the Pax-QNR/Pax-6 gene can produce proteins with two DNA-binding domains as well as proteins containing only the DNA-binding homeodomain.

scholarly journals Characterization of CprK1, a CRP/FNR-Type Transcriptional Regulator of Halorespiration from Desulfitobacterium hafniense

2006 ◽  
Vol 188 (7) ◽  
pp. 2604-2613 ◽  
Author(s):  
Krisztina Gábor ◽  
Carla S. Veríssimo ◽  
Barbara C. Cyran ◽  
Paul ter Horst ◽  
Nienke P. Meijer ◽  
...  
Keyword(s):  
Dna Binding ◽  
Redox Regulation ◽  
Physiological Role ◽  
Disulfide Bridge ◽  
Reductive Dehalogenation ◽  
Receptor Protein ◽  
Oxidative Inactivation ◽  
Desulfitobacterium Hafniense

ABSTRACT The recently identified CprK branch of the CRP (cyclic AMP receptor protein)-FNR (fumarate and nitrate reduction regulator) family of transcriptional regulators includes proteins that activate the transcription of genes encoding proteins involved in reductive dehalogenation of chlorinated aromatic compounds. Here we report the characterization of the CprK1 protein from Desulfitobacterium hafniense, an anaerobic low-G+C gram-positive bacterium that is capable of reductive dechlorination of 3-chloro-4-hydroxyphenylacetic acid (Cl-OHPA). The gene encoding CprK1 was cloned and functionally overexpressed in Escherichia coli, and the protein was subsequently purified to homogeneity. To investigate the interaction of CprK1 with three of its predicted binding sequences (dehaloboxes), we performed in vitro DNA-binding assays (electrophoretic mobility shift assays) as well as in vivo promoter probe assays. Our results show that CprK1 binds its target dehaloboxes with high affinity (dissociation constant, 90 nM) in the presence of Cl-OHPA and that transcriptional initiation by CprK1 is influenced by deviations in the dehaloboxes from the consensus TTAAT----ATTAA sequence. A mutant CprK1 protein was created by a Val→Glu substitution at a conserved position in the recognition α-helix that gained FNR-type DNA-binding specificity, recognizing the TTGAT----ATCAA sequence (FNR box) instead of the dehaloboxes. CprK1 was subject to oxidative inactivation in vitro, most likely caused by the formation of an intermolecular disulfide bridge between Cys11 and Cys200. The possibility of redox regulation of CprK1 by a thiol-disulfide exchange reaction was investigated by using two Cys→Ser mutants. Our results indicate that a Cys11-Cys200 disulfide bridge does not appear to play a physiological role in the regulation of CprK1.

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