• The Plant Pathology Journal
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• 제29권3호
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• pp.323-329
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• 2013

The stationary-phase sigma factor, RpoS, influences the expression of factors important in survival of Pseudomonas chlororaphis O6 in the rhizosphere. A partial proteomic profile of a rpoS mutant in P. chlororaphis O6 was conducted to identify proteins under RpoS regulation. Five of 14 differentially regulated proteins had unknown roles. Changes in levels of proteins in P. chlororaphis O6 rpoS mutant were associated with iron metabolism, and protection against oxidative stress. The P. chlororaphis O6 rpoS mutant showed increased production of a pyoverdine-like siderophore, indole acetic acid, and altered isozyme patterns for peroxidase, catalase and superoxide dismutase. Consequently, sensitivity to hydrogen peroxide exposure increased in the P. chlororaphis O6 rpoS mutant, compared with the wild type. Taken together, RpoS exerted regulatory control over factors important for the habitat of P. chlororaphis O6 in soil and on root surfaces. The properties of several of the proteins in the RpoS regulon are currently unknown.

• 미생물학회지
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• 제32권4호
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• pp.264-270
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• 1994

세균의 RNA 중합효소에서 여러 ${\sigma}$ 인자들 간에 보존된 아미노산 서열중 2.3 부위와 4.2 부위의 아미노산 서열로부터 유 n하여 두가지의 PCR primer를 제작하였다. 이들을 이용하여 PCR을 수행하였을 때, E. coli와 Streptomyces coelicolor의 DNA로부터 예상되었던 480 bp 정도의 DNA가 증폭되는 것을 관찰하였다. E. coli DNA에서 증폭된 DNA를 클로닝하여 염기서열을 결정한 결과 E. coli의 rpoS 유전자로부터 유래하였음을 알았다. 이를 탐침으로 S. coelicolor에서 genomic DNA hybridization을 수행하였을 때, PvuII 절편 두가지 (3.5 kb, 2.0 kb) 와 SalI 절편 두가지(3.4kb, 1.5 kb)에 탐침이 결합하는 것을 관찰하였다. 3.5 kb의 pvuII 절편을 sublibrary로부터 클로닝하고, 탐침이 결합하는 1.0kb의 BamHI/HincII 절편의 염기서열을 분석하였다. 부분적으로 결정된 염기서열을 BLAST 프로그램을 이용하여 GenBank와 EMBL, PDB 등의 data library의 유전자들과 비교하여 본 결과Streptomyces속의 ${\sigma}$인자들을 비롯한 Synechococcus종, Anabaena종, Pseudomonas aeruginosa, Stigmatella aurantica 등의 주된 ${\sigma}$ 인자와 높은 유사성을 보였다. 현재까지 1.2 부위와 4 부위에 해당하는 부분의 염기서열을 결정하였는데, 이 부분은 S. coelicolor에서 알려진 다섯가지의 ${\sigma}$ 인자 유전자 중 hrdA와 가장 높은 유사성을 보이며, 아미노산의 유사성이 1.2부위에서는 88%, 4 부위에서는 75%인 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.280-283
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• 1998

We have cloned the RNA polymerase sigma-like factors from a wide range of actinomycetes by using specific primers with the polymerase chain reaction (PCR). The specific oligonucleotide primers were designed on the basis of amino acid sequences of conserved regions from HrdA, B, D of Streptomyces griseus as well as from the rpoD box of many eubacteria. The consensus sequences were from the rpoD box and helix-turn-helix motif involved in -35 recognition. The designed primers were successfully applied to amplify the DNA fragments of the hrd homolog genes from 8 different strains of actinomycetes which produce a wide variety of important antibiotics. The 480 bp of the DNA fragment was amplified from all 8 strains, and it was identified as a part of hrdA and hrdB as we designed. The deduced amino acid sequence of PCR-amplified DNA fragments were highly homologous to those of other known RNA polymerase sigma factors of S. griseus and Streptomyces aureofaciens. Therefore, this study with specifically designed primers will support rapid cloning of the RNA polymerase sigma factors which recognize different classes of promoters from actinomycetes, and it will also be helpful in understanding the relationship of promoters and sigma factors leading to heterogeneity of RNA polymerases in actinomycetes.

• 한국어병학회지
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• 제30권2호
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• pp.79-88
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• 2017

현재 양식장에서는 Aeromonad를 비롯한 다양한 병원균에 의한 전염병으로 인해 많은 경제적 손실을 겪고 있다. 연어과 어류뿐만 아니라 담수 및 해수어류에도 치명적인 감염을 야기하는 Aeromonas 종은 적어도 26종 이상이 보고되어왔으며, 전염병을 유발하는 유비쿼터스 세균이다. Aeromonas 종을 확인하기 위해 16S rDNA 및 하우스 키핑 유전자의 핵산 서열을 기반으로 한 분자생물학적 기술이 사용될 수 있다. 본 연구에서 Aeromonas 종은 강원도 16개 양식장의 연어과 어류로부터 분리되었으며 Aeromonad의 16S rDNA와 하우스 키핑 유전자의 서열, 즉 RNA polymerase sigma factor ${\sigma}^{70}$ (rpoD) 또는 DNA gyrase subunit B (gyrB)를 기반으로 계통 발생 학적으로 동정했다. 그 결과 대서양 연어 (Salmo salar), 은연어 (Oncorhynchus keta), 산천어 (Oncorhynchus masou masou), 무지개송어 (Oncorhynchus mykiss)에서 96 개의 균주가 수집되었으며, 36개의 균주가 16S rDNA 분석에 의해 Aeromonas 속으로 확인되었다. 확인된 Aeromonas 속 균주는 rpoD 또는 gyrB 유전자 서열을 기반으로 추가 분석되어 Aeromonas salmonicida (24 균주), A. sobria (10 균주), A. media (1 균주) 및 A. popoffii (1 균주)로 검출되었으며, 이 것은 Aeromonas salmonicida가 강원도의 연어과 어류에서 주요 감염균임을 나타낸다. 또 하우스 키핑 유전자의 서열에 기초한 Aeromonas 종의 계통발생학적 동정은 16S rDNA 서열보다 더 정확하다는 것이 또한 증명되었다.

• 미생물학회지
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• 제49권3호
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• pp.215-220
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• 2013

많은 세균들은 환경적 스트레스에 대항하기 위해 세균 생존에 유용한 특정 유전자들의 전사를 유도하는 대체시그마 인자 RpoS를 활용한다. 세포 내 RpoS 단백질의 농도는 주로 ClpXP 단백질 분해효소의 조절을 통해 결정된다. RpoS를 ClpXP로 전달하기 위해서는 adaptor 단백질 RssB가 반드시 필요하다. Two-component-type response regulator RssB는 RpoS와 지속적으로 상호작용을 하지만, 다양한 환경변화에 의해 RssB-RpoS 상호작용이 억제되어 세균에서 RpoS 양을 증가시킨다. 본 총설에서는 최근까지 연구 된 RssB-RpoS 상호작용에 관여하는 RssB의 anti-adaptor 단백질 IraD, IraM, IraP 등의 조절인자들과 RssB의 N-terminal 수용체 도메인의 인산화에 대해 설명하고 요약하였다. 이러한 RssB의 정교한 활성을 통한 RpoS 분해조절 과정은 외부환경 스트레스로부터 보다 효율적으로 세균을 보호할 수 있다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.100.2-101
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• 2003

The global regulator, GacS (global antibiotic and cyanide sensor kinase), was required for the increased resistance to hydrogen peroxide occurring as cultures of the rhizobacterium, P. chlororaphis O6, matured. Specific stationary-phase peroxidase and catalase isozymes were absent in the GacS mutant, whereas a manganese-superoxide dismutase isozyme was expressed earlier and to a great extent than wild type. In the wild type cell, transcript accumulation of rpoS was higher in late logarithmic-phase cells than cells from mid logarithmic- or stationary-phase. Transcripts from rpoS in the GacS mutant were reduced in each of these growth phases compared to the wild type expression. The down stream sequence from rpoS lacked sequences encoding a small RNA, rsmZ, found in other pseudomonads and implicated in control of genes activated by the GacS system. These findings suggest that GacS-mediated regulation of RpoS plays role in control of oxidative stress in P. chlororaphis O6 by as yet an unknown mechanism.

• Journal of Microbiology
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• 제41권2호
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• pp.109-114
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• 2003

A promoter that is inducible by paraquat and menadione, the superoxide generators, independently of soxRS has been found in front of the sufABCDSE operon in Escherichia coli. Based on the observation that SufA is a holomog of IscA that functions in the assembly of iron sulfur cluster and the sufA promoter (sufAp) contains a putative Fur-binding consensus, we investigated whether this gene is regulated by Fur, a ferric uptake regulator, When examined in several sufAp-lacZ chromosomal fusion strains, sufAp was induced by EDTA, an iron chelator and a well-known Fur-inducer, The basal level of sufA expression increased dramatically in fur mutant, suggesting repression of sufAp by Fur. The derepression in fur mutant and EDTA-induction of sufA expression required nucleotides up to -61, where a putative Fur box is located. Purified Fur protein bound to the DNA fragment containing the putative Fur box between -35 and -10 promoter elements. The regulation by Fur and menadione induction of sufAp acted independently. The rpoS mutation increased sufA induction by menadione, suggesting that the stationary sigma factor RpoS acts negatively on sufA induction.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.226.1-226
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• 1999

No Abstract, See Full Text

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.99.1-100
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• 2003

E. intermedium Blocontrol activity of a P. chlororaphis rhizobacteium O6, depends to the synthesis of extracellular secondary metabolites and exoenzymes, thought to antagonize the pathogenicity of a variety of phytopathogenic fungi. The production of secondary metabolites and exoenzymes in O6, depends essentially on the GacS-mediated signal transduction pathway, which activates largely unknown signal transduction pathway. To exploit the GacS-mediated signal transdcution pathway involved in activation of ph genes that are necessary for biosynthesis of phenazine from P. chlororaphis O6, we cloned and sequenced the phz operon, rpoS gene encoding stationary specific sigma factor, ppx gene encoding polyphosphatase, and lon gene encoding ion protease. Expression of each gene in wild type and GacS mutant were analyzed by RT-PCR. Transcripts from rpoS, phzI enconing acylhomoserine lactone (AHL) synthase, and ph structural genes in the GacS mutant were reduced in each of these growth phases compared to the wild type. The GacS or Lon mutant was found to be deficient in the production of phenzines, exoenzymes, and the acylhomoserine lactone. These mutants were not complemented by ph operon and addition of exogenous AHL. These results indicate that the GacS global regulatory systems controls phenazine production at multiple levels. Future research will focus to identifying the GacS-mediated regulatory cascade involving in production of phenazine in P. chlororaphis.

• International Journal of Oral Biology
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• 제39권4호
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• pp.207-213
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• 2014

Antimicrobial actions of reactive oxygen/nitrogen species (ROS/RNS) derived from products of NADPH oxidase and inducible nitric oxide (NO) synthase in host phagocytes inactivate various bacterial macromolecules. To cope with these cytotoxic radicals, pathogenic bacteria have evolved to conserve systems necessary for detoxifying ROS/RNS and repairing damages caused by their actions. In response to these stresses, bacteria also induce expression of molecular chaperones to aid in ameliorating protein misfolding. In this study, we explored the function of a newly identified chaperone Spy, that is localized exclusively in the periplasm when bacteria exposed to conditions causing spheroplast formation, in the resistance of Salmonella Typhimurium to ROS/RNS. A spy deletion mutant was constructed in S. Typhimurium by a PCR-mediated method of one-step gene inactivation with ${\lambda}$ Red recombinase, and subjected to ROS/RNS stresses. The spy mutant Salmonella showed a modest decrease in growth rate in NO-producing cultures, and no detectable difference of growth rate in $H_2O_2$ containing cultures, compared with that of wild type Salmonella. Quantitative RT-PCR analysis showed that spy mRNA levels were similar regardless of both stresses, but were increased considerably in Salmonella mutants lacking the flavohemoglobin Hmp, which are incapable of NO detoxification, and lacking an alternative sigma factor RpoS, conferring hypersusceptibility to $H_2O_2$. Results demonstrate that Spy expression can be induced under extreme conditions of both stresses, and suggest that the protein may have supportive roles in maintaining proteostasis in the periplasm where various chaperones may act in concert with Spy, thereby protecting bacteria against toxicities of ROS/RNS.