Divergent promoters (bifunctional promoters)

2015 ◽  
pp. 1-1
Keyword(s):  
Divergent Promoters

Analysis of the promoter activities of the genes encoding three quinoprotein alcohol dehydrogenases in Pseudomonas putida HK5

Microbiology ◽  
2009 ◽  
Vol 155 (2) ◽  
pp. 594-603 ◽  
Author(s):  
Worrawat Promden ◽  
Alisa S. Vangnai ◽  
Hirohide Toyama ◽  
Kazunobu Matsushita ◽  
Piamsook Pongsawasdi
Keyword(s):  
Transcriptional Regulation ◽  
Pseudomonas Putida ◽  
Regulatory Network ◽  
Alcohol Oxidation ◽  
Gene Products ◽  
Response Regulators ◽  
Divergent Promoters ◽  
Promoter Probe ◽  
Genes Encoding ◽  
Promoter Probe Vector

The transcriptional regulation of three distinct alcohol oxidation systems, alcohol dehydrogenase (ADH)-I, ADH-IIB and ADH-IIG, in Pseudomonas putida HK5 was investigated under various induction conditions. The promoter activities of the genes involved in alcohol oxidation were determined using a transcriptional lacZ fusion promoter-probe vector. Ethanol was the best inducer for the divergent promoters of qedA and qedC, encoding ADH-I and a cytochrome c, respectively. Primary and secondary C3 and C4 alcohols and butyraldehyde specifically induced the divergent promoters of qbdBA and aldA, encoding ADH-IIB and an NAD-dependent aldehyde dehydrogenase, respectively. The qgdA promoter of ADH-IIG responded well to (S)-(+)-1,2-propanediol induction. In addition, the roles of genes encoding the response regulators exaE and agmR, located downstream of qedA, were inferred from the properties of exaE- or agmR-disrupted mutants and gene complementation tests. The gene products of both exaE and agmR were strictly necessary for qedA transcription. The mutation and complementation studies also suggested a role for AgmR, but not ExaE, in the transcriptional regulation of qbdBA (ADH-IIB) and qgdA (AGH-IIG). A hypothetical scheme describing a regulatory network, which directs expression of the three distinct alcohol oxidation systems in P. putida HK5, was derived.

scholarly journals RegA Control of Bacteriochlorophyll and Carotenoid Synthesis in Rhodobacter capsulatus

2007 ◽  
Vol 189 (21) ◽  
pp. 7765-7773 ◽  
Author(s):  
Jonathan Willett ◽  
James L. Smart ◽  
Carl E. Bauer
Keyword(s):  
Rhodobacter Capsulatus ◽  
Protoporphyrin Ix ◽  
Carotenoid Biosynthesis ◽  
Divergent Promoters ◽  
Anaerobic Induction ◽  
Single Region ◽  
Phytoene Dehydrogenase ◽  
Carotenoid Synthesis

ABSTRACT We provide in vivo genetic and in vitro biochemical evidence that RegA directly regulates bacteriochlorophyll and carotenoid biosynthesis in Rhodobacter capsulatus. β-Galactosidase expression assays with a RegA-disrupted strain containing reporter plasmids for Mg-protoporphyrin IX monomethyl ester oxidative cyclase (bchE), Mg-protoporphyrin IX chelatase (bchD), and phytoene dehydrogenase (crtI) demonstrate RegA is responsible for fourfold anaerobic induction of bchE, threefold induction of bchD, and twofold induction of crtI. Promoter mapping studies, coupled with DNase I protection assays, map the region of RegA binding to three sites in the bchE promoter region. Similar studies at the crtA and crtI promoters indicate that RegA binds to a single region equidistant from these divergent promoters. These results demonstrate that RegA is directly responsible for anaerobic induction of bacteriochlorophyll biosynthesis genes bchE, bchD, bchJ, bchI, bchG, and bchP and carotenoid biosynthesis genes crtI, crtB, and crtA.

scholarly journals Fimbrial ghf Gene Cluster of Genital Strains of Haemophilus spp.

2002 ◽  
Vol 70 (10) ◽  
pp. 5438-5445 ◽  
Author(s):  
Guillaume Bruant ◽  
Nathalie Gousset ◽  
Roland Quentin ◽  
Agnes Rosenau
Keyword(s):  
Gene Cluster ◽  
Chromosome Analysis ◽  
Gene Clusters ◽  
Large Deletion ◽  
Gene Promoters ◽  
Rt Pcr ◽  
Divergent Promoters ◽  
Intergenic Regions ◽  
Flanking Regions ◽  
Palindromic Sequences

ABSTRACT We analyzed the LKP fimbrial gene clusters of six piliated strains of a cryptic genospecies of Haemophilus isolated from the genital tracts of adult patients (five strains) and from an infected neonate. In a group of 19 genital strains, LKP-like genes have been found in only these 6 strains. In addition to the ghfA, ghfD, and ghfE genes previously described, we characterized two genes, designated ghfB and ghfC, encoding the putative chaperone and assembly platform proteins. All six strains had a complete and unique LKP-like gene cluster consisting of the five genes ghfA to ghfE, homologous to genes hifA to hifE of Haemophilus influenzae. The sequences of the coding and intergenic regions of the ghf clusters of the six strains were remarkably homologous. Unlike hif clusters, which are inserted between purE and pepN, the ghf cluster was inserted between purK and pepN on the chromosome. Analysis of the flanking regions of the ghf cluster identified a large deletion, identical in the 5′ end regions of all strains, including the whole purE gene and much of the purK gene. Ultrastructural observations, an attempt at enriching LKP fimbriae, and hemagglutination experiments demonstrated that none of the strains had LKP-type fimbriae. Nevertheless, reverse transcription (RT)-PCR showed that ghf genes were transcribed in four of the six strains. Sequencing of the intergenic ghfA-ghfB regions, including the ghf gene promoters, showed that the absence of transcripts in the remaining two strains was due to a decrease in the number of TA repeats (4 or 9 repeats rather than 10) between the −10 and −35 boxes of the two overlapping and divergent promoters. The other four strains, which had ghf transcripts, had the optimal 10 TA repeats (one strain) or 5 repeats associated with putative alternative −35 boxes (three strains). The absence of 10 repeated palindromic sequences of 44 or 45 nucleotides upstream of ghfB induces an increased instability of mRNA, as quantified by real-time RT-PCR, and may explain why the LKP fimbrial gene cluster is not expressed in these strains.

scholarly journals Regulation of the yjjQ-bglJ Operon, Encoding LuxR-Type Transcription Factors, and the Divergent yjjP Gene by H-NS and LeuO

2007 ◽  
Vol 190 (3) ◽  
pp. 926-935 ◽  
Author(s):  
Thomas Stratmann ◽  
S. Madhusudan ◽  
Karin Schnetz
Keyword(s):  
Transcription Factors ◽  
Virulence Factor ◽  
Binding Sites ◽  
Regulatory Region ◽  
Gene Encoding ◽  
E Coli ◽  
Divergent Promoters ◽  
Nucleoprotein Complex ◽  
K 12 ◽  
Regulatory Sites

ABSTRACT The yjjQ and bglJ genes encode LuxR-type transcription factors conserved in several enterobacterial species. YjjQ is a potential virulence factor in avian pathogenic Escherichia coli. BglJ counteracts the silencing of the bgl (β-glucoside) operon by H-NS in E. coli K-12. Here we show that yjjQ and bglJ form an operon carried by E. coli K-12, whose expression is repressed by the histone-like nucleoid structuring (H-NS) protein. The LysR-type transcription factor LeuO counteracts this repression. Furthermore, the yjjP gene, encoding a membrane protein of unknown function and located upstream in divergent orientation to the yjjQ-bglJ operon, is likewise repressed by H-NS. Mapping of the promoters as well as the H-NS and LeuO binding sites within the 555-bp intergenic region revealed that H-NS binds to the center of the AT-rich regulatory region and distal to the divergent promoters. LeuO sites map to the center and to positions distal to the yjjQ promoters, while one LeuO binding site overlaps with the divergent yjjP promoter. This latter LeuO site is required for full derepression of the yjjQ promoters. The arrangement of regulatory sites suggests that LeuO restructures the nucleoprotein complex formed by H-NS. Furthermore, the data support the conclusion that LeuO, whose expression is likewise repressed by H-NS and which is a virulence factor in Salmonella enterica, is a master regulator that among other loci, also controls the yjjQ-bglJ operon and thus indirectly the presumptive targets of YjjQ and BglJ.

scholarly journals Identification of Operators and Promoters That Control SXT Conjugative Transfer

2004 ◽  
Vol 186 (17) ◽  
pp. 5945-5949 ◽  
Author(s):  
John W. Beaber ◽  
Matthew K. Waldor
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Conjugative Transfer ◽  
Multiple Antibiotic Resistance ◽  
Divergent Promoters

ABSTRACT Transfer of SXT, a Vibrio cholerae-derived integrating conjugative element that encodes multiple antibiotic resistance genes, is repressed by SetR, a λ434 cI-related repressor. Here we identify divergent promoters between s086 and setR that drive expression of the regulators of SXT transfer. One transcript encodes the activators of transfer, setC and setD. The second transcript codes for SetR and, like the cI transcript of lambda, is leaderless. SetR binds to four operators located between setR and s086; the locations and relative affinities of these sites suggest a model for regulation of SXT transfer.

scholarly journals A Complex Genetic Switch Involving Overlapping Divergent Promoters and DNA Looping Regulates Expression of Conjugation Genes of a Gram-positive Plasmid

PLoS Genetics ◽  
2014 ◽  
Vol 10 (10) ◽  
pp. e1004733 ◽  
Author(s):  
Gayetri Ramachandran ◽  
Praveen K. Singh ◽  
Juan Roman Luque-Ortega ◽  
Luis Yuste ◽  
Carlos Alfonso ◽  
...  
Keyword(s):  
Dna Looping ◽  
Gram Positive ◽  
Genetic Switch ◽  
Divergent Promoters

scholarly journals Functional Analysis and Regulation of the Divergent spuABCDEFGH-spuI Operons for Polyamine Uptake and Utilization in Pseudomonas aeruginosa PAO1

2002 ◽  
Vol 184 (14) ◽  
pp. 3765-3773 ◽  
Author(s):  
Chung-Dar Lu ◽  
Yoshifumi Itoh ◽  
Yuji Nakada ◽  
Ying Jiang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcription Initiation ◽  
Regulatory Protein ◽  
Induction Effect ◽  
Two Component System ◽  
S1 Nuclease ◽  
Inducible Promoters ◽  
Divergent Promoters ◽  
Knockout Mutants ◽  
Polyamine Uptake

ABSTRACT A multiple-gene locus for polyamine uptake and utilization was discovered in Pseudomonas aeruginosa PAO1. This locus contained nine genes designated spuABCDEFGHI (spu for spermidine and putrescine utilization). The physiological functions of the spu genes in utilization of two polyamines (putrescine and spermidine) were analyzed by using Tn5 transposon-mediated spu knockout mutants. Growth and uptake experiments support that the spuDEFGH genes specify components of a major ABC-type transport system for spermidine uptake, and enzymatic measurements indicated that spuC encodes putrescine aminotransferase with pyruvate as the amino group receptor. Although spuA and spuB mutants showed an apparent defect in spermidine utilization, the biochemical functions of the gene products have yet to be elucidated. Assays of lacZ fusions demonstrated the presence of agmatine-, putrescine-, and spermidine-inducible promoters for the spuABCDEFGH operon and the divergently transcribed spuI gene of unknown function. Since the observed induction effect of agmatine was abolished in an aguA mutant where conversion of agmatine into putrescine was blocked, putrescine or spermidine, but not agmatine, serves as the inducer molecule of the spuA-spuI divergent promoters. S1 nuclease mappings confirmed further the induction effects of the polyamines on transcription of the divergent promoters and localized the transcription initiation sites. Gel retardation assays with extracts from the cells grown on putrescine or spermidine demonstrated the presence of a polyamine-responsive regulatory protein interacting with the divergent promoter region. Finally, the absence of the putrescine-inducible spuA expression and putrescine aminotransferase (spuC) formation in the cbrB mutant indicated that the spu operons are regulated by the global CbrAB two-component system perhaps via the putative polyamine-responsive transcriptional activator.

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