scholarly journals PapR6, a Putative Atypical Response Regulator, Functions as a Pathway-Specific Activator of Pristinamycin II Biosynthesis in Streptomyces pristinaespiralis

2014 ◽  
Vol 197 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Junling Dun ◽  
Yawei Zhao ◽  
Guosong Zheng ◽  
Hong Zhu ◽  
Lijun Ruan ◽  
...  
Keyword(s):  
Response Regulator ◽  
Biosynthetic Gene Cluster ◽  
Transcriptional Analysis ◽  
Upstream Region ◽  
Binding Motif ◽  
Regulation Mechanism ◽  
Mobility Shift ◽  
Content Type ◽  
Streptomyces Pristinaespiralis ◽  
Specific Regulation

There are up to seven regulatory genes in the pristinamycin biosynthetic gene cluster ofStreptomyces pristinaespiralis, which infers a complicated regulation mechanism for pristinamycin production. In this study, we revealed that PapR6, a putative atypical response regulator, acts as a pathway-specific activator of pristinamycin II (PII) biosynthesis. Deletion of thepapR6gene resulted in significantly reduced PII production, and its overexpression led to increased PII formation, compared to that of the parental strain HCCB 10218. However, eitherpapR6deletion or overexpression had very little effect on pristinamycin I (PI) biosynthesis. Electrophoretic mobility shift assays (EMSAs) demonstrated that PapR6 bound specifically to the upstream region ofsnaF, the first gene of thesnaFE1E2GHIJKoperon, which is likely responsible for providing the precursor isobutyryl-coenzyme A (isobutyryl-CoA) and the intermediate C11αβ-unsaturated thioester for PII biosynthesis. A signature PapR6-binding motif comprising two 4-nucleotide (nt) inverted repeat sequences (5′-GAGG-4 nt-CCTC-3′) was identified. Transcriptional analysis showed that inactivation of thepapR6gene led to markedly decreased expression ofsnaFE1E2GHIJK. Furthermore, we found that a mutant (snaFmu) with base substitutions in the identified PapR6-binding sequence in the genome exhibited the same phenotype as that of the ΔpapR6strain. Therefore, it may be concluded that pathway-specific regulation of PapR6 in PII biosynthesis is possibly exerted via controlling the provision of isobutyryl-CoA as well as the intermediate C11αβ-unsaturated thioester.

scholarly journals GouR, a TetR Family Transcriptional Regulator, Coordinates the Biosynthesis and Export of Gougerotin in Streptomyces graminearus

2013 ◽  
Vol 80 (2) ◽  
pp. 714-722 ◽  
Author(s):  
Junhong Wei ◽  
Yuqing Tian ◽  
Guoqing Niu ◽  
Huarong Tan
Keyword(s):  
Biological Activities ◽  
Regulatory Protein ◽  
Specific Inhibitor ◽  
Biosynthetic Gene Cluster ◽  
Binding Activity ◽  
Major Facilitator Superfamily ◽  
Transcriptional Analysis ◽  
Mobility Shift ◽  
Content Type ◽  
Inhibitor Of Protein Synthesis

ABSTRACTGougerotin is a peptidyl nucleoside antibiotic. It functions as a specific inhibitor of protein synthesis by binding ribosomal peptidyl transferase and exhibits a broad spectrum of biological activities.gouR, situated in the gougerotin biosynthetic gene cluster, encodes a TetR family transcriptional regulatory protein. Gene disruption and genetic complementation revealed thatgouRplays an important role in the biosynthesis of gougerotin. Transcriptional analysis suggested that GouR represses the transcription of thegouL-to-gouBoperon consisting of 11 structural genes and activates the transcription of the major facilitator superfamily (MFS) transporter gene (gouM). Electrophoresis mobility shift assays (EMSAs) and DNase I footprinting experiments showed that GouR has specific DNA-binding activity for the promoter regions ofgouL,gouM, andgouR. Our data suggested that GouR modulates gougerotin production by coordinating its biosynthesis and export inStreptomyces graminearus.

scholarly journals The Bacillus subtilis Response Regulator GenedegUIs Positively Regulated by CcpA and by Catabolite-Repressed Synthesis of ClpC

2012 ◽  
Vol 195 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Hiroshi Ishii ◽  
Teruo Tanaka ◽  
Mitsuo Ogura
Keyword(s):  
Bacillus Subtilis ◽  
Response Regulator ◽  
Consensus Sequence ◽  
Protein A ◽  
Upstream Region ◽  
Sporulation Medium ◽  
Mobility Shift ◽  
Content Type ◽  
Cellular Processes ◽  
Mobility Shift Assay

ABSTRACTInBacillus subtilis, the response regulator DegU and its cognate kinase, DegS, constitute a two-component system that regulates many cellular processes, including exoprotease production and genetic competence. Phosphorylated DegU (DegU-P) activates its own promoter and is degraded by the ClpCP protease. We observed induction ofdegUby glucose in sporulation medium. This was abolished in two mutants: theccpA(catabolite control protein A) andclpCdisruptants. Transcription of the promoter of the operon containingclpC(PclpC) decreased in the presence of glucose, and the disruption ofccpAresulted in derepression of PclpC. However, this was not directly mediated by CcpA, because we failed to detect binding of CcpA to PclpC. Glucose decreased the expression ofclpC, leading to low cellular concentrations of the ClpCP protease. Thus,degUis induced through activation of autoregulation by a decrease in ClpCP-dependent proteolysis of DegU-P. An electrophoretic mobility shift assay showed that CcpA bound directly to thedegUupstream region, indicating that CcpA activatesdegUthrough binding. The bound region was narrowed down to 27 bases, which contained acre(catabolite-responsiveelement) sequence with a low match to thecreconsensus sequence. In a footprint analysis, CcpA specifically protected a region containing thecresequence from DNase I digestion. The induction ofdegUby glucose showed complex regulation of thedegUgene.

scholarly journals Involvement of PatE, a Prophage-Encoded AraC-Like Regulator, in the Transcriptional Activation of Acid Resistance Pathways of Enterohemorrhagic Escherichia coli Strain EDL933

2012 ◽  
Vol 78 (15) ◽  
pp. 5083-5092 ◽  
Author(s):  
Jennifer K. Bender ◽  
Judyta Praszkier ◽  
Matthew J. Wakefield ◽  
Kathryn Holt ◽  
Marija Tauschek ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Transcriptional Activation ◽  
Regulatory Protein ◽  
Acid Resistance ◽  
Enterohemorrhagic Escherichia Coli ◽  
Transcriptional Analysis ◽  
Mobility Shift ◽  
Content Type ◽  
Infectious Dose ◽  
Genes Encoding

ABSTRACTEnterohemorrhagicEscherichia coli(EHEC) O157:H7 is a lethal human intestinal pathogen that causes hemorrhagic colitis and the hemolytic-uremic syndrome. EHEC is transmitted by the fecal-oral route and has a lower infectious dose than most other enteric bacterial pathogens in that fewer than 100 CFU are able to cause disease. This low infectious dose has been attributed to the ability of EHEC to survive in the acidic environment of the human stomach.In silicoanalysis of the genome of EHEC O157:H7 strain EDL933 revealed a gene,patE, for a putative AraC-like regulatory protein within the prophage island, CP-933H. Transcriptional analysis inE. colishowed that the expression ofpatEis induced during stationary phase. Data from microarray assays demonstrated that PatE activates the transcription of genes encoding proteins of acid resistance pathways. In addition, PatE downregulated the expression of a number of genes encoding heat shock proteins and the type III secretion pathway of EDL933. Transcriptional analysis and electrophoretic mobility shift assays suggested that PatE also activates the transcription of the gene for the acid stress chaperonehdeAby binding to its promoter region. Finally, assays of acid tolerance showed that increasing the expression of PatE in EHEC greatly enhanced the ability of the bacteria to survive in different acidic environments. Together, these findings indicate that EHEC strain EDL933 carries a prophage-encoded regulatory system that contributes to acid resistance.

scholarly journals A Complex Signaling Cascade Governs Pristinamycin Biosynthesis in Streptomyces pristinaespiralis

2015 ◽  
Vol 81 (19) ◽  
pp. 6621-6636 ◽  
Author(s):  
Yvonne Mast ◽  
Jamil Guezguez ◽  
Franziska Handel ◽  
Eva Schinko
Keyword(s):  
Response Regulator ◽  
Receptor Gene ◽  
Signaling Cascade ◽  
Regulator Gene ◽  
Biosynthetic Gene ◽  
Content Type ◽  
Streptomyces Pristinaespiralis ◽  
Complex Signaling ◽  
Tetr Repressor ◽  
Insight Into

ABSTRACTPristinamycin production inStreptomyces pristinaespiralisPr11 is tightly regulated by an interplay between different repressors and activators. A γ-butyrolactone receptor gene (spbR), two TetR repressor genes (papR3andpapR5), three SARP (Streptomycesantibioticregulatoryprotein) genes (papR1,papR2, andpapR4), and a response regulator gene (papR6) are carried on the large 210-kb pristinamycin biosynthetic gene region ofStreptomyces pristinaespiralisPr11. A detailed investigation of all pristinamycin regulators revealed insight into a complex signaling cascade, which is responsible for the fine-tuned regulation of pristinamycin production inS. pristinaespiralis.

scholarly journals Efficient Production of Polymyxin in the Surrogate Host Bacillus subtilis by Introducing a ForeignectBGene and Disrupting theabrBGene

2012 ◽  
Vol 78 (12) ◽  
pp. 4194-4199 ◽  
Author(s):  
Soo-Young Park ◽  
Soo-Keun Choi ◽  
Jihoon Kim ◽  
Tae-Kwang Oh ◽  
Seung-Hwan Park
Keyword(s):  
Bacillus Subtilis ◽  
Paenibacillus Polymyxa ◽  
Biosynthetic Gene Cluster ◽  
Upstream Region ◽  
Efficient Production ◽  
Knockout Mutant ◽  
Double Knockout ◽  
Gene Encoding ◽  
Content Type ◽  
Surrogate Host

ABSTRACTIn our previous study,Bacillus subtilisstrain BSK3S, containing a polymyxin biosynthetic gene cluster fromPaenibacillus polymyxa, could produce polymyxin only in the presence of exogenously addedl-2,4-diaminobutyric acid (Dab). The dependence of polymyxin production on exogenous Dab was removed by introducing anectBgene encoding the diaminobutyrate synthase ofP. polymyxainto BSK3S (resulting in strain BSK4). We found, by observing the complete inhibition of polymyxin synthesis when thespo0Agene was knocked out (strain BSK4-0A), that Spo0A is indispensable for the production of polymyxin. Interestingly, theabrB-spo0Adouble-knockout mutant, BSK4-0A-rB, and the singleabrBmutant, BSK4-rB, showed 1.7- and 2.3-fold increases, respectively, in polymyxin production over that of BSK4. These results coincided with the transcription levels ofpmxAin the strains observed by quantitative real-time PCR (qRT-PCR). The AbrB protein was shown to bind directly to the upstream region ofpmxA, indicating that AbrB directly inhibits the transcription of polymyxin biosynthetic genes. The BSK4-rB strain, producing high levels of polymyxin, will be useful for the development and production of novel polymyxin derivatives.

scholarly journals Hierarchical control of virginiamycin production in Streptomyces virginiae by three pathway-specific regulators: VmsS, VmsT and VmsR

Microbiology ◽  
2009 ◽  
Vol 155 (4) ◽  
pp. 1250-1259 ◽  
Author(s):  
Nattika Pulsawat ◽  
Shigeru Kitani ◽  
Eriko Fukushima ◽  
Takuya Nihira
Keyword(s):  
Gene Cluster ◽  
Response Regulator ◽  
Expression Profiles ◽  
Regulatory Protein ◽  
Regulatory Region ◽  
Biosynthetic Gene Cluster ◽  
Transcriptional Analysis ◽  
Biosynthetic Gene ◽  
Biosynthetic Genes ◽  
Streptomyces Virginiae

Two regulatory genes encoding a Streptomyces antibiotic regulatory protein (vmsS) and a response regulator (vmsT) of a bacterial two-component signal transduction system are present in the left-hand region of the biosynthetic gene cluster of the antibiotic virginiamycin, which is composed of virginiamycin M (VM) and virginiamycin S (VS), in Streptomyces virginiae. Disruption of vmsS abolished both VM and VS biosynthesis, with drastic alteration of the transcriptional profile for virginiamycin biosynthetic genes, whereas disruption of vmsT resulted in only a loss of VM biosynthesis, suggesting that vmsS is a pathway-specific regulator for both VM and VS biosynthesis, and that vmsT is a pathway-specific regulator for VM biosynthesis alone. Gene expression profiles determined by semiquantitative RT-PCR on the virginiamycin biosynthetic gene cluster demonstrated that vmsS controls the biosynthetic genes for VM and VS, and vmsT controls unidentified gene(s) of VM biosynthesis located outside the biosynthetic gene cluster. In addition, transcriptional analysis of a deletion mutant of vmsR located in the clustered regulatory region in the virginiamycin cluster (and which also acts as a SARP-family activator for both VM and VS biosynthesis) indicated that the expression of vmsS and vmsT is under the control of vmsR, and vmsR also contributes to the expression of VM and VS biosynthetic genes, independent of vmsS and vmsT. Therefore, coordinated virginiamycin biosynthesis is controlled by three pathway-specific regulators which hierarchically control the expression of the biosynthetic gene cluster.

scholarly journals RifZ (AMED_0655) Is a Pathway-Specific Regulator for Rifamycin Biosynthesis in Amycolatopsis mediterranei

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
Chen Li ◽  
Xinqiang Liu ◽  
Chao Lei ◽  
Han Yan ◽  
Zhihui Shao ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Dna Sequences ◽  
Consensus Sequence ◽  
Biosynthetic Gene Cluster ◽  
High Yield ◽  
Biosynthetic Gene ◽  
Amycolatopsis Mediterranei ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Content Type

ABSTRACT Rifamycin and its derivatives are particularly effective against the pathogenic mycobacteria Mycobacterium tuberculosis and Mycobacterium leprae. Although the biosynthetic pathway of rifamycin has been extensively studied in Amycolatopsis mediterranei, little is known about the regulation in rifamycin biosynthesis. Here, an in vivo transposon system was employed to identify genes involved in the regulation of rifamycin production in A. mediterranei U32. In total, nine rifamycin-deficient mutants were isolated, among which three mutants had the transposon inserted in AMED_0655 (rifZ, encoding a LuxR family regulator). The rifZ gene was further knocked out via homologous recombination, and the transcription of genes in the rifamycin biosynthetic gene cluster (rif cluster) was remarkably reduced in the rifZ null mutant. Based on the cotranscription assay results, genes within the rif cluster were grouped into 10 operons, sharing six promoter regions. By use of electrophoretic mobility shift assay and DNase I footprinting assay, RifZ was proved to specially bind to all six promoter regions, which was consistent with the fact that RifZ regulated the transcription of the whole rif cluster. The binding consensus sequence was further characterized through alignment using the RifZ-protected DNA sequences. By use of bionformatic analysis, another five promoters containing the RifZ box (CTACC-N8-GGATG) were identified, among which the binding of RifZ to the promoter regions of both rifK and orf18 (AMED_0645) was further verified. As RifZ directly regulates the transcription of all operons within the rif cluster, we propose that RifZ is a pathway-specific regulator for the rif cluster. IMPORTANCE To this day, rifamycin and its derivatives are still the first-line antituberculosis drugs. The biosynthesis of rifamycin has been extensively studied, and most biosynthetic processes have been characterized. However, little is known about the regulation of the transcription of the rifamycin biosynthetic gene cluster (rif cluster), and no regulator has been characterized. Through the employment of transposon screening, we here characterized a LuxR family regulator, RifZ, as a direct transcriptional activator for the rif cluster. As RifZ directly regulates the transcription of the entire rif cluster, it is considered a pathway-specific regulator for rifamycin biosynthesis. Therefore, as the first regulator characterized for direct regulation of rif cluster transcription, RifZ may provide a new clue for further engineering of high-yield industrial strains.

scholarly journals Serratia marcescensarn, a PhoP-Regulated Locus Necessary for Polymyxin B Resistance

2014 ◽  
Vol 58 (9) ◽  
pp. 5181-5190 ◽  
Author(s):  
Quei Yen Lin ◽  
Yi-Lin Tsai ◽  
Ming-Che Liu ◽  
Wei-Cheng Lin ◽  
Po-Ren Hsueh ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Response Regulator ◽  
Challenge Test ◽  
Polymyxin B ◽  
Resistant Bacteria ◽  
Wild Type ◽  
Mobility Shift ◽  
Content Type ◽  
In The Wild

ABSTRACTPolymyxins, which are increasingly being used to treat infections caused by multidrug-resistant bacteria, perform poorly againstSerratia marcescens. To investigate the underlying mechanisms, Tn5mutagenesis was performed and two mutants exhibiting increased polymyxin B (PB) susceptibility were isolated. The mutants were found to have Tn5inserted into thearnBandarnCgenes. In other bacteria,arnBandarnCbelong to the seven-genearnoperon, which is involved in lipopolysaccharide (LPS) modification. LPSs ofarnmutants had greater PB-binding abilities than that of wild-type LPS. Further, we identified PhoP, a bacterial two-component response regulator, as a regulator of PB susceptibility inS. marcescens. By the reporter assay, we found PB- and low-Mg2+-induced expression ofphoPandarnin the wild-type strain but not in thephoPmutant. Complementation of thephoPmutant with the full-lengthphoPgene restored the PB MIC and induction by PB and low Mg2+levels, as in the wild type. An electrophoretic mobility shift assay (EMSA) further demonstrated that PhoP bound directly to thearnpromoter. The PB challenge test confirmed that pretreatment with PB and low Mg2+levels protectedS. marcescensfrom a PB challenge in the wild-type strain but not in thephoPmutant. Real-time reverse transcriptase-PCR also indicated that PB serves as a signal to regulate expression ofugd, a gene required for LPS modification, inS. marcescensthrough a PhoP-dependent pathway. Finally, we found that PB-resistant clinical isolates displayed greater expression ofarnAupon exposure to PB than did susceptible isolates. This is the first report to describe the role ofS. marcescensarnin PB resistance and its modulation by PB and Mg2+through the PhoP protein.

scholarly journals Sycrp2 Is Essential for Twitching Motility in the CyanobacteriumSynechocystissp. Strain PCC 6803

2018 ◽  
Vol 200 (21) ◽  
Author(s):  
Wei-Yu Song ◽  
Sha-Sha Zang ◽  
Zheng-Ke Li ◽  
Guo-Zheng Dai ◽  
Ke Liu ◽  
...  
Keyword(s):  
Cell Motility ◽  
Receptor Protein ◽  
Upstream Region ◽  
Twitching Motility ◽  
Camp Receptor Protein ◽  
Mobility Shift ◽  
Content Type ◽  
Receptor Proteins ◽  
Camp Receptor ◽  
Pcc 6803

ABSTRACTTwo cAMP receptor proteins (CRPs), Sycrp1 (encoded bysll1371) and Sycrp2 (encoded bysll1924), exist in the cyanobacteriumSynechocystissp. strain PCC 6803. Previous studies have demonstrated that Sycrp1 has binding affinity for cAMP and is involved in motility by regulating the formation of pili. However, the function of Sycrp2 remains unknown. Here, we report thatsycrp2disruption results in the loss of motility ofSynechocystissp. PCC 6803, and that the phenotype can be recovered by reintroducing thesycrp2gene into the genome ofsycrp2-disrupted mutants. Electron microscopy showed that thesycrp2-disrupted mutant lost the pilus apparatus on the cell surface, resulting in a lack of cell motility. Furthermore, the transcript level of thepilA9-pilA11operon (essential for cell motility and regulated by the cAMP receptor protein Sycrp1) was markedly decreased insycrp2-disrupted mutants compared with the wild-type strain. Moreover, yeast two-hybrid analysis and a pulldown assay demonstrated that Sycrp2 interacted with Sycrp1 to form a heterodimer and that Sycrp1 and Sycrp2 interacted with themselves to form homodimers. Gel mobility shift assays revealed that Sycrp1 specifically binds to the upstream region ofpilA9. Together, these findings indicate that inSynechocystissp. PCC 6803, Sycrp2 regulates the formation of pili and cell motility by interacting with Sycrp1.IMPORTANCEcAMP receptor proteins (CRPs) are widely distributed in cyanobacteria and play important roles in regulating gene expression. Although many cyanobacterial species have two cAMP receptor-like proteins, the functional links between them are unknown. Here, we found that Sycrp2 in the cyanobacteriumSynechocystissp. strain PCC 6803 is essential for twitching motility and that it interacts with Sycrp1, a known cAMP receptor protein involved with twitching motility. Our findings indicate that the two cAMP receptor-like proteins in cyanobacteria do not have functional redundancy but rather work together.

scholarly journals Synergistic Activation of the Pathogenicity-Related Proline Iminopeptidase Gene in Xanthomonas campestris pv. campestris by HrpX and a LuxR Homolog

2012 ◽  
Vol 78 (19) ◽  
pp. 7069-7074 ◽  
Author(s):  
Jingxi Zhang ◽  
Jinhong Kan ◽  
Jieqiong Zhang ◽  
Ping Guo ◽  
Xiaoying Chen ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Fusion Gene ◽  
Inducible Promoter ◽  
Upstream Region ◽  
Mobility Shift ◽  
Content Type ◽  
Pulldown Assay ◽  
Synergistic Activation ◽  
Mobility Shift Assay ◽  
Proline Iminopeptidase

ABSTRACTXanthomonas campestrispv. campestris strain 8004 contains an orphan quorum-sensing (QS) locus,xccR-pipXcc, in which the proline iminopeptidase (pipXcc) gene (where “Xcc” indicates that thepipgene is fromX. campestrispv. campestris) is positively regulated by the LuxR homologue XccR by binding to theluxXcbox of thepipXccpromoter. The disruption ofpipXccsignificantly attenuated the virulence ofX. campestrispv. campestris. An imperfect plant-inducible promoter (PIP) box is located in the upstream region of thepipXccpromoter, which is the putative binding site of the transcriptional activator HrpX. To explore whether the expression of thepipXccgene is regulated by HrpX, the expression level of apipXccpromoter-gusAfusion gene was assayed in anhrpXdisruption mutant. The results showed that the lack of HrpX dramatically decreased the β-glucuronidase (GUS) activity. Further analyses using an electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP)-PCR indicated that the imperfect PIP box inX. campestrispv. campestris is specifically bound to HrpX. These data demonstrated that thepipXccgene belongs to the hrp regulon and that the imperfect PIP box of thepipXccpromoter could be aciselement for the HrpX protein. We further showed in a pulldown assay that XccR can bind HrpX, suggesting that these two regulatory proteins coactivate the virulence factor by binding to the differentciselements of thepipXccgene and adapt to the host environment duringX. campestrispv. campestris infection.

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