scholarly journals A genomic island of Streptomyces coelicolor with the self-contained regulon of an ECF sigma factor

2018 ◽  
Author(s):  
Camilla M. Kao ◽  
Nitsara Karoonuthaisiri ◽  
David Weaver ◽  
Jonathan A. Vroom ◽  
Shuning A. Gai ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Sigma Factor ◽  
Genomic Island ◽  
Streptomyces Coelicolor ◽  
Sigma Factors ◽  
Genomic Islands ◽  
Biologically Active ◽  
Transcriptional Unit ◽  
Ecf Sigma Factor

AbstractStreptomycetes constitute the largest genus of actinobacteria, living predominantly in soil and decaying vegetation. The bacteria are widely known for their filamentous morphologies and their capacity to synthesize antibiotics and other biologically active molecules. More than a decade ago, we and others identified 22 genomic islands thatStreptomyces coelicolorM145 possesses and otherStreptomycesstrains lack. One of these genomic islands, Genomic Island (GI) 6, encodes an extracytoplasmic function (ECF) sigma factor that we were characterizing in separate work. Here we report that artificial induction of the ECF sigma factor, which is encoded by SCO3450, causes the transcription of approximately one-fourth of GI 6, or ~26 mostly contiguous genes, to increase. More than half of the regulon encodes putative enzymes involved in small molecule metabolism. A putative haloacid dehalogenase is present. Genes encoding two putative anti-sigma factors flank SCO3450, the three genes residing within the regulon. Our data suggest that the ECF sigma factor and its regulon are a self-contained transcriptional unit that can be transferred by horizontal gene transfer. To our knowledge, only one other example has been identified of an ECF sigma factor and its contiguous regulon appearing to be transferrable by horizontal gene transfer [18,19]. Because the regulon appears not to be induced by the 44 growth conditions recently examined by Byung-Kwan Cho and colleagues [20], if it confers fitness toS. coelicolor, the regulon likely does so in as-yet unknown situations. Those situations might range from scavenging to detoxification to even communication within microbial communities.IMPORTANCEStreptomycesbacteria grow as hyphae that colonize soil and differentiate into spores when nutrients become scarce. In their terrestrial habitats, the bacteria encounter diverse conditions. Presumably so that the bacteria can cope with those conditions, the chromosomes of streptomycetes are highly dynamic, varying greatly in structure not only between species but also between closely related strains of a single species. The bacteria also have large numbers of extracytoplasmic function (ECF) sigma factors, which undoubtedly help the microorganisms respond to the plethora of challenges coming from the environment. This work illustrates these two threads ofStreptomycesbiology dovetailing: Genetic adaptability through horizontal gene transfer seems to have enabledStreptomyces coelicolorto acquire a self-contained transcriptional unit that consists of an ECF sigma factor and its regulon. The suggested facile movement of the regulon between microbial hosts indicates the value of the metabolism of small molecules possibly mediated by the regulon.

scholarly journals Genomic Islands in the Corynebacterium efficiens Genome

2005 ◽  
Vol 71 (6) ◽  
pp. 3126-3130 ◽  
Author(s):  
Ren Zhang ◽  
Chun-Ting Zhang
Keyword(s):  
Thermal Stability ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Genomic Island ◽  
Genomic Islands ◽  
Aspartate Kinase ◽  
Gene Encoding ◽  
Profile Method ◽  
Adaptive Mutations ◽  
Thermal Stability Of

ABSTRACT Corynebacterium efficiens is a gram-positive nonpathogenic bacterium which can grow and produce glutamate at 40°C or above. By using the cumulative GC profile method, we have identified four genomic islands which have many unifying genomic island-specific features in the C. efficiens genome. The presence of the gene encoding an aspartate kinase in a genomic island helps explain the unexpected low thermal stability of this enzyme; i.e., the adaptive mutations have not occurred extensively due to the recent horizontal gene transfer.

scholarly journals The ECF sigma factor PvdS regulates the type I-F CRISPR-Cas system in Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Stephen Dela Ahator ◽  
Wang Jianhe ◽  
Lian-Hui Zhang
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Sigma Factor ◽  
Regulatory System ◽  
Stress Factors ◽  
Iron Limitation ◽  
Transport Systems ◽  
Type I ◽  
Ecf Sigma Factor ◽  
Wide Range

AbstractDuring infection, successful colonization of bacteria requires a fine-tuned supply of iron acquired via iron transport systems. However, the transport systems serve as phage attachment sites and entry portals for foreign nucleic acid. Most bacteria possess the CRISPR-Cas system, which targets and destroys foreign nucleic acids and prevents deleterious effects of horizontal gene transfer. To understand the regulation of the CRISPR-Cas system, we performed genome-wide random transposon mutagenesis which led to the identification of the Extracytoplasmic Function (ECF) Sigma factor, PvdS as a regulator of the Type I-F CRISPR-Cas system in P. aeruginosa. We show that under iron-depleted conditions PvdS induces the expression of the type I-F CRISPR-Cas system. This regulatory mechanism involves direct interaction of PvdS with specific binding sites in the promoter region of cas1. Furthermore, activation of the CRISPR-Cas system under iron-depleted conditions increases horizontal gene transfer (HGT) interference and adaptation. The PvdS activation of the CRISPR-Cas system under iron limitation highlights the versatility of the P. aeruginosa in multitasking its regulatory machinery to integrate multiple stress factors.ImportanceP. aeruginosa infects a wide range of host organisms and adapts to various environmental stress factors such as iron limitation due to its elaborate regulatory system. P aeruginosa possesses the type I-F CRISPR-Cas system as a defense mechanism against phages infection and HGT. This work highlights the ability of P. aeruginosa to multitask its iron regulatory system to control the CRISPR-Cas system under a physiologically relevant stress factor such as iron limitation where the bacteria are vulnerable to phage infection. It also adds to the knowledge of the regulation of the CRISPR-Cas system in bacteria and presents a possible target that could prevent the emergence of phage resistance via the CRISPR-Cas system during the development of phage therapy.

scholarly journals panRGP: a pangenome-based method to predict genomic islands and explore their diversity

2020 ◽  
Vol 36 (Supplement_2) ◽  
pp. i651-i658 ◽  
Author(s):  
Adelme Bazin ◽  
Guillaume Gautreau ◽  
Claudine Médigue ◽  
David Vallenet ◽  
Alexandra Calteau
Keyword(s):  
Escherichia Coli ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Species Level ◽  
Genomic Islands ◽  
Genome Plasticity ◽  
Reference Dataset ◽  
Prokaryotic Genomes ◽  
Ideal Approach ◽  
Genomic Regions

Abstract Motivation Horizontal gene transfer (HGT) is a major source of variability in prokaryotic genomes. Regions of genome plasticity (RGPs) are clusters of genes located in highly variable genomic regions. Most of them arise from HGT and correspond to genomic islands (GIs). The study of those regions at the species level has become increasingly difficult with the data deluge of genomes. To date, no methods are available to identify GIs using hundreds of genomes to explore their diversity. Results We present here the panRGP method that predicts RGPs using pangenome graphs made of all available genomes for a given species. It allows the study of thousands of genomes in order to access the diversity of RGPs and to predict spots of insertions. It gave the best predictions when benchmarked along other GI detection tools against a reference dataset. In addition, we illustrated its use on metagenome assembled genomes by redefining the borders of the leuX tRNA hotspot, a well-studied spot of insertion in Escherichia coli. panRPG is a scalable and reliable tool to predict GIs and spots making it an ideal approach for large comparative studies. Availability and implementation The methods presented in the current work are available through the following software: https://github.com/labgem/PPanGGOLiN. Detailed results and scripts to compute the benchmark metrics are available at https://github.com/axbazin/panrgp_supdata.

Pleiotropic anti-anti-sigma factor BldG is phosphorylated by several anti-sigma factor kinases in the process of activating multiple sigma factors in Streptomyces coelicolor A3(2)

Gene ◽  
2020 ◽  
Vol 755 ◽  
pp. 144883
Author(s):  
Beatrica Sevcikova ◽  
Bronislava Rezuchova ◽  
Erik Mingyar ◽  
Dagmar Homerova ◽  
Renata Novakova ◽  
...  
Keyword(s):  
Sigma Factor ◽  
Streptomyces Coelicolor ◽  
Sigma Factors

scholarly journals Phylogenomic Analyses of Non-Dikarya Fungi Supports Horizontal Gene Transfer Driving Diversification of Secondary Metabolism in the Amphibian Gastrointestinal Symbiont, Basidiobolus

2020 ◽  
Vol 10 (9) ◽  
pp. 3417-3433
Author(s):  
Javier F Tabima ◽  
Ian A Trautman ◽  
Ying Chang ◽  
Yan Wang ◽  
Stephen Mondo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Secondary Metabolism ◽  
Gene Clusters ◽  
Biologically Active ◽  
Constitutive Gene Expression ◽  
Gut Symbionts ◽  
Phylogenomic Analyses ◽  
Siderophore Activity

Abstract Research into secondary metabolism (SM) production by fungi has resulted in the discovery of diverse, biologically active compounds with significant medicinal applications. The fungi rich in SM production are taxonomically concentrated in the subkingdom Dikarya, which comprises the phyla Ascomycota and Basidiomycota. Here, we explore the potential for SM production in Mucoromycota and Zoopagomycota, two phyla of nonflagellated fungi that are not members of Dikarya, by predicting and identifying core genes and gene clusters involved in SM. The majority of non-Dikarya have few genes and gene clusters involved in SM production except for the amphibian gut symbionts in the genus Basidiobolus. Basidiobolus genomes exhibit an enrichment of SM genes involved in siderophore, surfactin-like, and terpene cyclase production, all these with evidence of constitutive gene expression. Gene expression and chemical assays also confirm that Basidiobolus has significant siderophore activity. The expansion of SMs in Basidiobolus are partially due to horizontal gene transfer from bacteria, likely as a consequence of its ecology as an amphibian gut endosymbiont.

scholarly journals Variability in Assembly of Degradation Operons for Naphthalene and its derivative, Carbaryl, Suggests Mobilization through Horizontal Gene Transfer

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 569 ◽  
Author(s):  
Phale ◽  
Shah ◽  
Malhotra
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Food Web ◽  
Microbial Communities ◽  
Metabolic Pathways ◽  
Anthropogenic Activities ◽  
Genetic Material ◽  
Genomic Islands ◽  
Biochemical Pathways ◽  
Integrative Conjugative Elements

In the biosphere, the largest biological laboratory, increased anthropogenic activities have led microbes to evolve and adapt to the changes occurring in the environment. Compounds, specifically xenobiotics, released due to such activities persist in nature and undergo bio-magnification in the food web. Some of these compounds act as potent endocrine disrupters, mutagens or carcinogens, and therefore their removal from the environment is essential. Due to their persistence, microbial communities have evolved to metabolize them partially or completely. Diverse biochemical pathways have evolved or been assembled by exchange of genetic material (horizontal gene transfer) through various mobile genetic elements like conjugative and non-conjugative plasmids, transposons, phages and prophages, genomic islands and integrative conjugative elements. These elements provide an unlimited opportunity for genetic material to be exchanged across various genera, thus accelerating the evolution of a new xenobiotic degrading phenotype. In this article, we illustrate examples of the assembly of metabolic pathways involved in the degradation of naphthalene and its derivative, Carbaryl, which are speculated to have evolved or adapted through the above-mentioned processes.

scholarly journals BldG and SCO3548 Interact Antagonistically To Control Key Developmental Processes in Streptomyces coelicolor

2009 ◽  
Vol 191 (8) ◽  
pp. 2541-2550 ◽  
Author(s):  
Archana Parashar ◽  
Kimberley R. Colvin ◽  
Dawn R. D. Bignell ◽  
Brenda K. Leskiw
Keyword(s):  
Sigma Factor ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Affinity Purification ◽  
Regulatory System ◽  
Direct Interaction ◽  
Morphological Differentiation ◽  
Sigma Factors ◽  
Developmental Processes ◽  
Two Hybrid

ABSTRACT The similarity of BldG and the downstream coexpressed protein SCO3548 to anti-anti-sigma and anti-sigma factors, respectively, together with the phenotype of a bldG mutant, suggests that BldG and SCO3548 interact as part of a regulatory system to control both antibiotic production and morphological differentiation in Streptomyces coelicolor. A combination of bacterial two-hybrid, affinity purification, and far-Western analyses demonstrated that there was self-interaction of both BldG and SCO3548, as well as a direct interaction between the two proteins. Furthermore, a genetic complementation experiment demonstrated that SCO3548 antagonizes the function of BldG, similar to other anti-anti-sigma/anti-sigma factor pairs. It is therefore proposed that BldG and SCO3548 form a partner-switching pair that regulates the function of one or more sigma factors in S. coelicolor. The conservation of bldG and sco3548 in other streptomycetes demonstrates that this system is likely a key regulatory switch controlling developmental processes throughout the genus Streptomyces.

scholarly journals Genomic islands: tools of bacterial horizontal gene transfer and evolution

2009 ◽  
Vol 33 (2) ◽  
pp. 376-393 ◽  
Author(s):  
Mario Juhas ◽  
Jan Roelof van der Meer ◽  
Muriel Gaillard ◽  
Rosalind M. Harding ◽  
Derek W. Hood ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Genomic Islands

scholarly journals ςBldN, an Extracytoplasmic Function RNA Polymerase Sigma Factor Required for Aerial Mycelium Formation in Streptomyces coelicolor A3(2)

2000 ◽  
Vol 182 (16) ◽  
pp. 4606-4616 ◽  
Author(s):  
Maureen J. Bibb ◽  
Virginie Molle ◽  
Mark J. Buttner
Keyword(s):  
Rna Polymerase ◽  
Sigma Factor ◽  
Streptomyces Coelicolor ◽  
Aerial Mycelium ◽  
Sigma Factors ◽  
Colony Development ◽  
Null Mutant ◽  
Wild Type

ABSTRACT Sporulation mutants of Streptomyces coelicolor appear white because they are defective in the synthesis of the gray polyketide spore pigment, and such white (whi) mutants have been used to define 13 sporulation loci. whiN, one of five new whi loci identified in a recent screen of NTG (N-methyl-N′-nitro-N-nitrosoguanidine)-inducedwhi strains (N. J. Ryding et al., J. Bacteriol. 181:5419–5425, 1999), was defined by two mutants, R112 and R650. R650 produced frequent spores that were longer than those of the wild type. In contrast, R112 produced long, straight, undifferentiated hyphae, although rare spore chains were observed, sometimes showing highly irregular septum placement. Subcloning and sequencing showed thatwhiN encodes a member of the extracytoplasmic function subfamily of RNA polymerase sigma factors and that the sigma factor has an unusual N-terminal extension of approximately 86 residues that is not present in other sigma factors. A constructed whiN null mutant failed to form aerial mycelium (the “bald” phenotype) and, as a consequence, whiN was renamed bldN. This observation was not totally unexpected because, on some media, the R112 point mutant produced substantially less aerial mycelium than its parent, M145. The bldN null mutant did not fit simply into the extracellular signaling cascade proposed for S. coelicolor bld mutants. Expression of bldN was analyzed during colony development in wild-type and aerial mycelium-deficientbld strains. bldN was transcribed from a single promoter, bldNp. bldN transcription was developmentally regulated, commencing approximately at the time of aerial mycelium formation, and depended on bldG and bldH, but not on bldA, bldB, bldC,bldF, bldK, or bldJ or onbldN itself. Transcription from the p1 promoter of the response-regulator gene bldM depended onbldN in vivo, and the bldMp1 promoter was shown to be a direct biochemical target for ςBldN holoenzyme in vitro.

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