scholarly journals Regulation of Hexuronate Utilization inBacillus subtilis

1999 ◽  
Vol 181 (2) ◽  
pp. 426-433 ◽  
Author(s):  
Kathleen R. Mekjian ◽  
Edward M. Bryan ◽  
Bernard W. Beall ◽  
Charles P. Moran
Keyword(s):  
Protein A ◽  
Repeat Sequence ◽  
Open Reading Frames ◽  
Erwinia Chrysanthemi ◽  
Inverted Repeat Sequence ◽  
Metabolic Genes ◽  
Catabolite Control Protein A ◽  
Regulated Expression ◽  
Control Protein ◽  
Reading Frames

ABSTRACT We have identified a locus essential for galacturonate utilization in Bacillus subtilis. Genes homologous to Escherichia coli and Erwinia chrysanthemi glucuronate and galacturonate metabolic genes were found in a cluster consisting of 10 open reading frames (ORFs) in the B. subtilis chromosome. A mutant of B. subtilis containing a replacement of the second and third ORFs was unable to grow with galacturonate as its primary carbon source. Galacturonate induced expression from a ςA-dependent promoter, exuP1, located upstream from the first ORF. The eighth ORF in this cluster (theexu locus) encodes a LacI and GalR homolog that negatively regulated expression from exuP1. A 26-bp inverted repeat sequence centered 15 bp downstream from the exuP1 start point of transcription acted in cis to negatively regulate expression from exuP1 under noninducing conditions. Expression from the exuP1 promoter was repressed by high levels of glucose, which is probably mediated by CcpA (catabolite control protein A). A ςE-dependent promoter,exuP2, was localized between the second and third ORFs and was active during sporulation.

Control of the glycolytic gapA operon by the catabolite control protein A in Bacillus subtilis: a novel mechanism of CcpA-mediated regulation

2002 ◽  
Vol 45 (2) ◽  
pp. 543-553 ◽  
Author(s):  
Holger Ludwig ◽  
Nicole Rebhan ◽  
Hans-Matti Blencke ◽  
Matthias Merzbacher ◽  
Jorg Stulke
Keyword(s):  
Bacillus Subtilis ◽  
Protein A ◽  
Catabolite Control Protein A ◽  
Control Protein ◽  
Catabolite Control

scholarly journals The yjeB (nsrR) Gene of Escherichia coli Encodes a Nitric Oxide-Sensitive Transcriptional Regulator

2006 ◽  
Vol 188 (3) ◽  
pp. 874-881 ◽  
Author(s):  
Diane M. Bodenmiller ◽  
Stephen Spiro
Keyword(s):  
Nitric Oxide ◽  
Escherichia Coli ◽  
Inverted Repeat ◽  
Nitrosative Stress ◽  
Protein A ◽  
Repeat Sequence ◽  
Negative Regulator ◽  
Inverted Repeat Sequence ◽  
Multiple Copies ◽  
Regulatory Model

ABSTRACT Microarray studies of the Escherichia coli response to nitric oxide and nitrosative stress have suggested that additional transcriptional regulators of this response remain to be characterized. We identify here the product of the yjeB gene as a negative regulator of the transcription of the ytfE, hmpA and ygbA genes, all of which are known to be upregulated by nitrosative stress. Transcriptional fusions to the promoters of these genes were expressed constitutively in a yjeB mutant, indicating that all three are targets for repression by YjeB. An inverted repeat sequence that overlaps the −10 element of all three promoters is proposed to be a binding site for the YjeB protein. A similar inverted repeat sequence was identified in the tehA promoter, which is also known to be sensitive to nitrosative stress. The ytfE, hmpA, ygbA, and tehA promoters all caused derepression of a ytfE-lacZ transcriptional fusion when present in the cell in multiple copies, presumably by a repressor titration effect, suggesting the presence of functional YjeB binding sites in these promoters. However, YjeB regulation of tehA was weak, as judged by the activity of a tehA-lacZ fusion, perhaps because YjeB repression of tehA is masked by other regulatory mechanisms. Promoters regulated by YjeB could be derepressed by iron limitation, which is consistent with an iron requirement for YjeB activity. The YjeB protein is a member of the Rrf2 family of transcriptional repressors and shares three conserved cysteine residues with its closest relatives. We propose a regulatory model in which the YjeB repressor is directly sensitive to nitrosative stress. On the basis of similarity to the nitrite-responsive repressor NsrR from Nitrosomonas europaea, we propose that the yjeB gene of E. coli be renamed nsrR.

scholarly journals NADP, corepressor for theBacilluscatabolite control protein CcpA

1998 ◽  
Vol 95 (16) ◽  
pp. 9590-9595 ◽  
Author(s):  
Jeong-Ho Kim ◽  
Martin I. Voskuil ◽  
Glenn H. Chambliss
Keyword(s):  
Dna Binding ◽  
Binding Affinity ◽  
Catabolite Repression ◽  
Protein A ◽  
Transcription Inhibition ◽  
Gram Positive Bacteria ◽  
Catabolite Control Protein A ◽  
Dna Binding Affinity ◽  
Reduced Forms ◽  
Control Protein

Expression of the α-amylase gene (amyE) ofBacillus subtilisis subject to CcpA (catabolite control protein A)-mediated catabolite repression, a global regulatory mechanism inBacillusand other Gram-positive bacteria. To determine effectors of CcpA, we tested the ability of glycolytic metabolites, nucleotides, and cofactors to affect CcpA binding to theamyEoperator,amyO. Those that stimulated the DNA-binding affinity of CcpA were tested for their effect on transcription. HPr-P (Ser-46), proposed as an effector of CcpA, also was tested. In DNase I footprint assays, the affinity of CcpA foramyOwas stimulated 2-fold by fructose-1,6-diphosphate (FDP), 1.5-fold by oxidized or reduced forms of NADP, and 10-fold by HPr-P (Ser-46). However, the triple combinations, CcpA/NADP/HPr-P (Ser-46) and CcpA/FDP/HPr-P (Ser-46) synergistically stimulated DNA-binding affinity by 120- and 300-fold, respectively. NADP added to CcpA specifically stimulated transcription inhibition of theamyEpromoter by 120-fold. CcpA combined with HPr (Ser-46) inhibited transcription from theamyEpromoter, but it also inhibited several control promoters. FDP did not stimulate transcription inhibition by CcpA nor did the triple combinations. The finding that NADP had little effect on CcpA DNA binding but increased the ability of CcpA to inhibit transcription suggests that catabolite repression is not simply caused by CcpA bindingamyObut rather a result of interactions with the transcription machinery enhanced by NADP.

scholarly journals Genomic Characterization of a Novel Freshwater Cyanophage Reveals a New Lineage of Cyanopodovirus

2022 ◽  
Vol 12 ◽  
Author(s):  
Dong Zhang ◽  
Yiliang He ◽  
Karina Yew-Hoong Gin
Keyword(s):  
Open Reading Frames ◽  
Metabolic Genes ◽  
Genes Encoding ◽  
Genomic Characterization ◽  
Ecological Importance ◽  
Auxiliary Metabolic Genes ◽  
Reading Frames ◽  
Tropical Freshwater ◽  
Core Genes

Cyanobacteria are one of the dominant autotrophs in tropical freshwater communities, yet phages infecting them remain poorly characterized. Here we present the characterization of cyanophage S-SRP02, isolated from a tropical freshwater lake in Singapore, which infects Synechococcus sp. Strain SR-C1 isolated from the same lake. S-SRP02 represents a new evolutionary lineage of cyanophage. Out of 47 open reading frames (ORFs), only 20 ORFs share homology with genes encoding proteins of known function. There is lack of auxiliary metabolic genes which was commonly found as core genes in marine cyanopodoviruses. S-SRP02 also harbors unique structural genes highly divergent from other cultured phages. Phylogenetic analysis and viral proteomic tree further demonstrate the divergence of S-SRP02 from other sequenced phage isolates. Nonetheless, S-SRP02 shares synteny with phage genes of uncultured phages obtained from the Mediterranean Sea deep chlorophyll maximum fosmids, indicating the ecological importance of S-SRP02 and its related viruses. This is further supported by metagenomic mapping of environmental viral metagenomic reads onto the S-SRP02 genome.

scholarly journals Catabolite Control Protein A (CcpA) Contributes to Virulence and Regulation of Sugar Metabolism in Streptococcus pneumoniae

2005 ◽  
Vol 187 (24) ◽  
pp. 8340-8349 ◽  
Author(s):  
Ramkumar Iyer ◽  
Nitin S. Baliga ◽  
Andrew Camilli
Keyword(s):  
Streptococcus Pneumoniae ◽  
Protein A ◽  
Sugar Metabolism ◽  
Invasive Disease ◽  
Sugar Uptake ◽  
Catabolite Control Protein A ◽  
Control Protein ◽  
Catabolite Control

ABSTRACT We characterized the role of catabolite control protein A (ccpA) in the physiology and virulence of Streptococcus pneumoniae. S. pneumoniae has a large percentage of its genome devoted to sugar uptake and metabolism, and therefore, regulation of these processes is likely to be crucial for fitness in the nasopharynx and may play a role during invasive disease. In many bacteria, carbon catabolite repression (CCR) is central to such regulation, influencing hierarchical sugar utilization and growth rates. CcpA is the major transcriptional regulator in CCR in several gram-positive bacteria. We show that CcpA functions in CCR of lactose-inducible β-galactosidase activity in S. pneumoniae. CCR of maltose-inducible α-glucosidase, raffinose-inducible α-galactosidase, and cellobiose-inducible β-glucosidase is unaffected in the ccpA strain, suggesting that other regulators, possibly redundant with CcpA, control these systems. The ccpA strain is severely attenuated for nasopharyngeal colonization and lung infection in the mouse, establishing its role in fitness on these mucosal surfaces. Comparison of the cell wall fraction of the ccpA and wild-type strains shows that CcpA regulates many proteins in this compartment that are involved in central and intermediary metabolism, a subset of which are required for survival and multiplication in vivo. Both in vitro and in vivo defects were complemented by providing ccpA in trans. Our results demonstrate that CcpA, though not a global regulator of CCR in S. pneumoniae, is required for colonization of the nasopharynx and survival and multiplication in the lung.

scholarly journals Transcriptome Analysis Reveals Catabolite Control Protein A Regulatory Mechanisms Underlying Glucose-Excess or -Limited Conditions in a Ruminal Bacterium, Streptococcus bovis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaqian Jin ◽  
Yaotian Fan ◽  
Hua Sun ◽  
Ying Zhang ◽  
Hongrong Wang
Keyword(s):  
Mutant Strain ◽  
Glucose Concentration ◽  
Type Strain ◽  
Wild Type Strain ◽  
Protein A ◽  
Regulatory Mechanisms ◽  
Streptococcus Bovis ◽  
Wild Type ◽  
Catabolite Control Protein A ◽  
Control Protein

Ruminants may suffer from rumen acidosis when fed with high-concentrate diets due to the higher proliferation and overproduction of lactate by Streptococcus bovis. The catabolite control protein A (CcpA) regulates the transcription of lactate dehydrogenase (ldh) and pyruvate formate-lyase (pfl) in S. bovis, but its role in response to different carbon concentrations remains unclear. To characterize the regulatory mechanisms of CcpA in S. bovis S1 at different levels of carbon, herein, we analyzed the transcriptomic and physiological characteristics of S. bovis S1 and its ccpA mutant strain grown in glucose-excess and glucose-limited conditions. A reduced growth rate and a shift in fermentation pattern from homofermentation to heterofermentation were observed under glucose-limited condition as compared to glucose-excess condition, in S. bovis S1. Additionally, the inactivation of ccpA significantly affected the growth and end metabolites in both conditions. For the glycolytic intermediate, fructose 1,6-bisphosphate (FBP), the concentration significantly reduced at lower glucose conditions; its concentration decreased significantly in the ccpA mutant strain. Transcriptomic results showed that about 46% of the total genes were differentially transcribed between the wild-type strain and ccpA mutant strain grown in glucose-excess conditions; while only 12% genes were differentially transcribed in glucose-limited conditions. Different glucose concentrations led to the differential expression of 38% genes in the wild-type strain, while only half of these were differentially expressed in the ccpA-knockout strain. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the substrate glucose concentration significantly affected the gene expression in histidine metabolism, nitrogen metabolism, and some carbohydrate metabolism pathways. The deletion of ccpA affected several genes involved in carbohydrate metabolism, such as glycolysis, pyruvate metabolism, fructose and mannose metabolism, as well as in fatty acid biosynthesis pathways in bacteria grown in glucose-excess conditions; this effect was attenuated under glucose-limited conditions. Overall, these findings provide new information on gene transcription and metabolic mechanisms associated with substrate glucose concentration and validate the important role of CcpA in the regulation of carbon metabolism in S. bovis S1 at differential glucose availability.

scholarly journals The HlyU Protein Is a Positive Regulator of rtxA1, a Gene Responsible for Cytotoxicity and Virulence in the Human Pathogen Vibrio vulnificus

2007 ◽  
Vol 75 (7) ◽  
pp. 3282-3289 ◽  
Author(s):  
Moqing Liu ◽  
Alejandro F. Alice ◽  
Hiroaki Naka ◽  
Jorge H. Crosa
Keyword(s):  
Transcription Initiation ◽  
Vibrio Vulnificus ◽  
Protein A ◽  
Open Reading Frames ◽  
Toxin Gene ◽  
Release Factor ◽  
Rapid Progress ◽  
Human Pathogen ◽  
Opportunistic Human Pathogen ◽  
Reading Frames

ABSTRACT Vibrio vulnificus is an opportunistic human pathogen that preferentially infects compromised iron-overloaded patients, causing a fatal primary septicemia with very rapid progress, resulting in a high mortality rate. In this study we determined that the HlyU protein, a virulence factor in V. vulnificus CMCP6, up-regulates the expression of VV20479, a homologue of the Vibrio cholerae RTX (repeats in toxin) toxin gene that we named rtxA1. This gene is part of an operon together with two other open reading frames, VV20481 and VV20480, that encode two predicted proteins, a peptide chain release factor 1 and a hemolysin acyltransferase, respectively. A mutation in rtxA1 not only contributes to the loss of cytotoxic activity but also results in a decrease in virulence, whereas a deletion of VV20481 and VV20480 causes a slight decrease in virulence but with no effect in cytotoxicity. Activation of the expression of the rtxA1 operon by HlyU occurs at the transcription initiation level by binding of the HlyU protein to a region upstream of this operon.

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