Role of <i>vapBC</i> toxin–antitoxin loci in the thermal stress response of <i>Sulfolobus solfataricus</i>

Cooper, Charlotte; Daugherty, Amanda; Tachdjian, Sabrina; Blum, Paul H.; Kelly, Robert M.

doi:10.1042/bst0370123

Cited by 63 publications

(52 citation statements)

References 41 publications

(35 reference statements)

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“…S3I in the supplemental material), which is widespread in archaea (44) and is also present in some archaeal plasmids (45). In the VapBC pair, VapC is the PIN domain containing RNase, whereas VapB is typically a transcription factor with the AbrB-like swapped-hairpin domain (46). As mentioned above, gp15 contains the AbrB-like DNA-binding domain and is encoded immediately upstream of ORF14, strongly suggesting that the two proteins, gp14 and gp15, constitute a functional toxin-antitoxin system of SNJ1.…”

Section: Resultsmentioning

confidence: 99%

Identification, Characterization, and Application of the Replicon Region of the Halophilic Temperate Sphaerolipovirus SNJ1

Wang

Sima

et al. 2016

J Bacteriol

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The temperate haloarchaeal virus SNJ1 displays lytic and lysogenic life cycles. During the lysogenic cycle, the virus resides in its host, Natrinema sp. strain J7-1, in the form of an extrachromosomal circular plasmid, pHH205. In this study, a 3.9-kb region containing seven predicted genes organized in two operons was identified as the minimal replicon of SNJ1. Only RepA, encoded by open reading frame 11-12 (ORF11-12), was found to be essential for replication, and its expression increased during the lytic cycle. Sequence analysis suggested that RepA is a distant homolog of HUH endonucleases, a superfamily that includes rollingcircle replication initiation proteins from various viruses and plasmids. In addition to RepA, two genetic elements located within both termini of the 3.9-kb replicon were also required for SNJ1 replication. SNJ1 genome and SNJ1 replicon-based shuttle vectors were present at 1 to 3 copies per chromosome. However, the deletion of ORF4 significantly increased the SNJ1 copy number, suggesting that the product of ORF4 is a negative regulator of SNJ1 abundance. Shuttle vectors based on the SNJ1 replicon were constructed and validated for stable expression of heterologous proteins, both in J7 derivatives and in Natrinema pallidum JCM 8980 T , suggesting their broad applicability as genetic tools for Natrinema species. IMPORTANCEArchaeal viruses exhibit striking morphological diversity and unique gene content. In this study, the minimal replicon of the temperate haloarchaeal virus SNJ1 was identified. A number of ORFs and genetic elements controlling virus genome replication, maintenance, and copy number were characterized. In addition, based on the replicon, a novel expression shuttle vector has been constructed and validated for protein expression and purification in Natrinema sp. CJ7 and Natrinema pallidum JCM 8980 T . This study not only provided mechanistic and functional insights into SNJ1 replication but also led to the development of useful genetic tools to investigate SNJ1 and other viruses infecting Natrinema species as well as their hosts. Haloarchaea are the dominant microbes in hypersaline environments, such as salt lakes and salterns. Viruses infecting haloarchaea outnumber their hosts by several orders of magnitude (1). It has been speculated that in such a harsh environment with no other predators, interactions between viruses and their hosts constitute the main evolutionary driving force (2). About 90 haloarchaeal viruses have been discovered so far, a relatively small number compared to the ϳ6,200 reported bacteriophages (3, 4). Given that the characterization of bacterial and eukaryotic viruses has yielded remarkable insights into the physiology and cell biology of their hosts, studies on haloarchaeal viruses are expected to be equally revealing. However, thus far, research has been limited by the scarcity of suitable and genetically tractable virus-host models. Consequently, most of the current knowledge on viral entry, transcription, genome replication, assembly, and ...

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Section: Resultsmentioning

confidence: 99%

Identification, Characterization, and Application of the Replicon Region of the Halophilic Temperate Sphaerolipovirus SNJ1

Wang

Sima

et al. 2016

J Bacteriol

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“…Archaeal plasmids encoding putative TA systems provide valuable models for the study of mechanisms and functions of the archaeal TA systems. However, none of these archaeal TA systems have functionally been characterized, except for a few Sulfolobus TA systems that were shown to be involved in the regulation of thermophily of the organism (225,226).…”

Section: Plasmid Functionsmentioning

confidence: 99%

Archaeal Extrachromosomal Genetic Elements

Wang

Peng

Shah

et al. 2015

Microbiol Mol Biol Rev

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SUMMARY Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spindles, rods, filaments, spheres, head-tails, bottles, and droplets, and some of these new viruses have been classified into one order, 10 families, and 16 genera. Investigation of model archaeal viruses has yielded important insights into mechanisms underlining various steps in the viral life cycle, including infection, DNA replication and transcription, and virion egression. Many of these mechanisms are unprecedented for any known bacterial or eukaryal viruses. Studies of plasmids isolated from different archaeal hosts have also revealed a striking diversity in gene content and innovation in replication strategies. Highly divergent replication proteins are identified in both viral and plasmid genomes. Genomic studies of archaeal ECEs have revealed a modular sequence structure in which modules of DNA sequence are exchangeable within, as well as among, plasmid families and probably also between viruses and plasmids. In particular, it has been suggested that ECE-host interactions have shaped the coevolution of ECEs and their archaeal hosts. Furthermore, archaeal hosts have developed defense systems, including the innate restriction-modification (R-M) system and the adaptive CRISPR (clustered regularly interspaced short palindromic repeats) system, to restrict invasive plasmids and viruses. Together, these interactions permit a delicate balance between ECEs and their hosts, which is vitally important for maintaining an innovative gene reservoir carried by ECEs. In conclusion, while research on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade.

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“…Walaupun demikian, belum banyak laporan mengenai hubungan toksisitas dengan ketahanan panas. Kajian keterkaitan gen toksik vapBC (virulence-associated protein) pada bakteri thermofilik Sulfolobus solfataricus menunjukkan bahwa gen tersebut berperan dalam stress response terhadap panas (Cooper et al 2009). …”

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APLIKASI MUTAN BERFLUORESENS UNTUK MEMPELAJARI KETAHANAN HIDUP, KOLONISASI DAN PENETRASI ISOLAT Cronobacter sakazakii SELAMA PENGERINGAN JAGUNG

Nurjanah

Suhartono

Dewanti‐Hariyadi

et al. 2013

jtip

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Cronobacter sakazakii is a Gram-negative emerging pathogen regarded as causative agent of meningitis and necrotizing enterocolitis in certain groups of infants. In the previous research, thirty-two local isolates of C. sakazakii were obtained from various dried food products such as from ABSTRAKCronobacter sakazakii merupakan bakteri Gram negatif yang dapat menyebabkan meningitis dan necrotizing enterocolitis pada kelompok bayi tertentu. Pada penelitian sebelumnya telah diisolasi tiga puluh dua isolat C. sakazakii dari beberapa produk pangan kering termasuk maizena, yang mengindikasikan ketahanan bakteri tersebut terhadap proses pengeringan. Sebagian isolat telah dievaluasi memiliki aktivitas toksik. Green Fluorescent Protein (GFP) telah berhasil disisipkan pada C. sakazakii dan digunakan sebagai penanda untuk perhitungan koloni secara selektif karena kemampuannya berfluoresens di bawah sinar UV dan tumbuh di media mengandung ampisilin. Penelitian ini bertujuan untuk mengevaluasi ketahanan hidup, kemampuan kolonisasi dan penetrasi dua isolat C. sakazakii selama proses pengeringan jagung menggunakan mutan berlabel GFP. Jagung diinokulasi dengan mutan pada konsentrasi 10 5 -10 6 CFU/g sebelum proses pengeringan. Pengeringan jagung dilakukan pada suhu 40, 45 dan 50ºC selama 4, 6 dan 8 hari sampai kadar air mencapai ≤14%. Jumlah koloni yang tahan terhadap pengeringan dihitung setiap hari pada media yang mengandung ampisilin melalui pengamatan di bawah sinar UV. Laju penurunan C. sakazakii selama pengeringan ditunjukkan oleh slope regresi linier dari kurva ketahanan hidup. Isolat toksik FWHd16 lebih tahan pada ke-3 suhu pengeringan dibandingkan dengan isolat nontoksik YRt2a. Pengamatan dengan mikroskop fluoresens dan SEM menunjukkan bahwa kedua isolat mampu berkolonisasi di permukaan jagung. Kedua isolat dapat berpenetrasi ke dalam jagung melalui bagian yang luka atau melalui rongga-rongga di bagian tip cap. Kata kunci:Cronobacter sakazakii, GFPuv, jagung, ketahanan hidup, mutan PENDAHULUAN1Cronobacter sakazakii merupakan salah satu dari 6 spesies dalam Genus Cronobacter spp. (sebelumnya dikenal sebagai Enterobacter sakazakii) (Iversen et al. 2008). Cronobacter spp. telah diisolasi dari berbagai sumber pangan, sumber klinis, dan Meutia et al. (2008), Gitapratiwi et al. (2012) dan Hamdani (2012. Semua isolat tersebut diperoleh dari produk pangan kering, yaitu susu formula, makanan pendamping ASI, maizena, tepung terigu, tapioka, coklat bubuk, gula halus serta rempah kering.

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Role of vapBC toxin–antitoxin loci in the thermal stress response of Sulfolobus solfataricus

Cited by 63 publications

References 41 publications

Identification, Characterization, and Application of the Replicon Region of the Halophilic Temperate Sphaerolipovirus SNJ1

Identification, Characterization, and Application of the Replicon Region of the Halophilic Temperate Sphaerolipovirus SNJ1

Archaeal Extrachromosomal Genetic Elements

APLIKASI MUTAN BERFLUORESENS UNTUK MEMPELAJARI KETAHANAN HIDUP, KOLONISASI DAN PENETRASI ISOLAT Cronobacter sakazakii SELAMA PENGERINGAN JAGUNG

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