• BMB Reports
• /
• 제30권1호
• /
• pp.66-72
• /
• 1997

A mammalian DNA repair enzyme, UV endonuclease III which also functions as a ribosomal protein S3 (rpS3), was purified from mouse cells and characterized. UV endonuclease III was previously cloned and known to yield a peptide of 32 kDa upon expression in E. coli [Kim et al., (1995) J. Bioi. Chem. 270, 13620-13629]. However, biochemically purified UV endonuclease III, which has a sedimentation coefficient of 3.25, appears to have an additional peptide of 28 kDa. It appears that two bands were derived from one complex, judging from the comparison of the nuclease activity on the native and SDS-gel electrophoreses. UV endonuclease III becomes non-specific upon purification and this phenomenon is more significant in the case of pure fractions of the enzyme. Non-specific activity was not influenced by pH or any salt conditions.

• Journal of Microbiology and Biotechnology
• /
• 제8권4호
• /
• pp.399-405
• /
• 1998

From the sequence alignment of various non-ribosomal peptide synthetases, several motifs of highly conserved sequences have been identified within each domain of peptide synthetases. We designed PCR primers based on the highly conserved nucleotide sequences to amplify and isolate a ∼7.2-kb DNA fragment of the Bacillus subtilis 713 which was isolated and reported to produce an antifungal peptide compound. Nucleotide sequence analysis of 4.8 kb of the predicted amino acids revealed significant homology to various peptide synthetases over the whole sequence and also revealed two amino acid-activating domains with highly conserved Core 1 to Core 6 and spacer motif. This suggests that the isolated DNA fragment is part of a peptide synthetase gene for antifungal peptide.

• KSBB Journal
• /
• 제22권5호
• /
• pp.362-365
• /
• 2007

Cyanobacterial A-domain의 A3 motif와 A7 motif의 높은 진화론적 보존성에 의거해서 Non-ribosomal peitides를 생산하는 시아노박테리아를 Screening할 수 있는 degenerated primer를 만들 수 있었다. Degenerate primer서열의 종류는 가능하면 1,000개 정도까지를 기준으로 만드는 것이 좋다. Primer의 종류가 너무 많으면 primer 1종류 당 mol수가 적게 되어 특이성도 저하된다. 그러므로 Primer의 종류가 많을 경우는 inosin을 N (4종류의 염기) 부분에 이용하면 어느 염기에도 강하게 결합하지 않고 두 가닥 DNA 형성을 저해하지도 않으므로 degeneration을 줄이는데 도움이 된다. Degenerate primer의 annealing 온도는 primer에 포함되어있는 서열 중 가장 낮은 Tm을 기준으로 한다. 이번 연구처럼 N (ACGT) 대신에 Inosin을 이용하였을 때에는 Inosin이 Tm을 높게 하지 않고 Tm을 낮게 하지도 않으므로 Tm 계산시 고려하지 않아도 되었다. PCR 효율이 떨어질 우려가 있으므로 충분한 Tm값 (대개 $45\sim60^{\circ}C$ 이상)을 갖는 서열을 디자인하여 primer로 PCR하는 것이 좋지만, A3/A7 degenerate prime에서는 실험에 의해 40$^{\circ}C$로 annealing 온도가 (Tm) 다소 낮게 설정되었다. 그러므로 검출되지 않은 NRPS gene을 가진 균주와 CBT635, CBT654와 같이 약한 PCR band의 형성은 새로 제작된 primer의 낮은 Tm 기인한다고 생각되어진다. Tm의 이론적인 값은 Tm ={(G+C)*4+(A+T)*2}의 식을 통해서 정방향 primer에서 54$^{\circ}C$ 역방향 primer에서 42$^{\circ}C$로 계산되었다. 새로운 degenerate primer에 의해서 MTF2/MTR2로 검출되지 않는 6개의 균주가 더 검출되었으며, A3/A7과 MTF2/MTR2를 이용한 통합 PCR Screening을 통해서 NRPS gene 검출에 특이성과 효율성을 높일 수 있다.

• KSBB Journal
• /
• 제23권5호
• /
• pp.398-402
• /
• 2008

Cyanobacteria havebeen identified as one of the most promising group producing novel biochemically active natural products. Cyanobacteria are a very old group of prokaryotic organisms that produce very diverse secondary metabolites, especially non-ribosomal peptide and polyketide structures. Though many useful natural products have been identified in cyanobacterial biomass, cyanobacteria produce also extracellular proteins related with NRPS/PKS. Detection of unknown secondary metabolites in medium was carried in the present study by a screening of 98 cyanobacterial strains. A degenerated PCR technique as molecular approaches was used for general screening of NRPS/PKS gene in cyanobacteria. A putative PKS gene was detected by DKF/DKR primer in 38 strains (38.8%) and PCR amplicons resulted from a presence of NRPS gene were showed by MTF2/MTR2 primer in 30 strains (30.6%) and by A3/A7 primer in 26 strains (26.5%). HPLC analysis for a detection of natural products was performed in extracts from medium in which cyanobacteria containing putative PKS or NRPS were cultivated. CBT57, CBT62, CBT590 and CBT632 strains were screened for a production of extracellular natural products. 5 pure substances were detected from medium of these cyanobacteria.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVII)
• /
• pp.996-996
• /
• 2005

• 미생물학회지
• /
• 제55권3호
• /
• pp.303-305
• /
• 2019

섬 해안가 토양에서 방선균주 Gordonia sp. MMS17-SY073를 분리하여 유전체 분석을 실시하였고, 그 결과 5,962,176 염기쌍 및 67.4%의 G + C 함량으로 이루어진 유전체 정보를 확보하였다. 유전정보 분석 결과 총 5,201개 단백질 지정 유전자, 6개 rRNA 유전자 및 45개 tRNA 유전자를 확인하였다. MMS17-SY073 균주는 16S rRNA 유전자를 이용한 분석 결과 분류학적으로 Gordonia soli의 표준균주와 가장 가까웠으며 그 유사도는 98.5%로 나타났다. MMS17-SY073 균주는 non-ribosomal peptide synthetase 유형을 비롯한 다수의 이차대사산물 생합성 유전자를 보유하고 있는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제28권7호
• /
• pp.1068-1077
• /
• 2018

DKxanthenes are a class of yellow secondary metabolites produced by myxobacterial genera Myxococcus and Stigmatella. We identified a putative 49.5 kb DKxanthene biosynthetic gene cluster from Myxococcus stipitatus DSM 14675 by genomic sequence and mutational analyses. The cluster consisted of 15 genes (MYSTI_06004-MYSTI_06018) encoding polyketide synthases, non-ribosomal peptide synthases, and proteins with unknown functions. Disruption of the genes by plasmid insertion resulted in defects in the production of yellow pigments. High-performance liquid chromatography and liquid chromatography-tandem mass spectrometry analyses indicated that the yellow pigments produced by M. stipitatus DSM 14675 might be novel DKxanthene derivatives. M. stipitatus did not require DKxanthenes for the formation of heat-resistant viable spores, unlike Myxococcus xanthus. Furthermore, DKxanthenes showed growth inhibitory activity against the fungi Aspergillus niger, Candida albicans, and Rhizopus stolonifer.

• Biomolecules & Therapeutics
• /
• 제27권2호
• /
• pp.127-133
• /
• 2019

The study of the genus Streptomyces is of particular interest because it produces a wide array of clinically important bioactive molecules. The genomic sequencing of many Streptomyces species has revealed unusually large numbers of cytochrome P450 genes, which are involved in the biosynthesis of secondary metabolites. Many macrolide biosynthetic pathways are catalyzed by a series of enzymes in gene clusters including polyketide and non-ribosomal peptide synthesis. In general, Streptomyces P450 enzymes accelerate the final, post-polyketide synthesis steps to enhance the structural architecture of macrolide chemistry. In this review, we discuss the major Streptomyces P450 enzymes research focused on the biosynthetic processing of macrolide therapeutic agents, with an emphasis on their biochemical mechanisms and structural insights.

• 한국미생물·생명공학회지
• /
• 제44권3호
• /
• pp.391-399
• /
• 2016

Melithiazol은 점액세균 Melitangium lichenicola, Archangium gephyra, Myxococcus stipitatus에 의해 생산되는 항진균 물질이다. M. lichenicola의 melithiazol 생합성 유전자는 이미 알려져 있지만, A. gephyra와 M. stipitatus의 melithiazol 생합성 유전자들은 아직까지 밝혀져 있지 않다. 본 연구에서는 유전체 서열 분석과 돌연변이 분석을 통해 M. stipitatus DSM 14675 균주로부터 37.3 kb 크기의 melithiazol 생합성 유전자군을 발견하였다. 이 유전자군은 9개(MYSTI_04973−MYSTI_04965)의 유전자로 구성되어 있는데, 4개의 polyketide synthase 모듈과 3개의 non-ribosomal peptide synthase 모듈, 그리고 fumarylacetoacetate hydrolase, S-adenosylmethionine-dependent methyltransferase, nitrilase를 암호화하는 것으로 분석되었다. 플라스미드 삽입 돌연변이를 통해 MYSTI_04972 유전자 또는 MYSTI_04973를 불활성화시켰을 때 melithiazol 생산능이 상실되었다. MYSTI_04972부터 MYSTI_04965까지의 8개 유전자가 암호화하는 melithiazol 생합성 모듈의 구성은 M. lichenicola Me l46에서와 유사하였다. 하지만 첫 번째 유전자(MYSTI_04973)에 의해 암호화되는 로딩 모듈의 구성은 M. lichenicola Me l46과 달랐는데, 이러한 차이는 M. stipitatus 균주들이 어떻게 M. lichenicola Me l46과는 다른 구조의 melithiazol 유도체들을 생산하는지 설명해준다.

• Journal of Microbiology and Biotechnology
• /
• 제30권5호
• /
• pp.689-699
• /
• 2020

Brevibacillus brevis GZDF3 is a gram-positive, plant growth-promoting rhizosphere bacterium (PGPR) isolated from the rhizosphere soil of Pinellia ternata (an important herb in traditional Chinese medicine). The GZDF3 strain produces certain active compounds, such as siderophores, which are the final metabolite products of non-ribosomal peptide synthetase (NRPS) and independent non-ribosomal peptide synthetase (NIS) activity. With the present study, we attempted to investigate the siderophore production characteristics and conditions of Bacillus sp. GZDF3. The antibacterial activity of the siderophores on pathogenic fungi was also investigated. Optimal conditions for the synthesis of siderophores were determined by single factor method, using sucrose 15 g/l, asparagine 2 g/l, 32℃, and 48 h. The optimized sucrose asparagine medium significantly increased the production of siderophores, from 27.09% to 54.99%. Moreover, the effects of different kinds of metal ions on siderophore production were explored here. We found that Fe³⁺ and Cu²⁺ significantly inhibited the synthesis of siderophores. The preliminary separation and purification of siderophores by immobilized-metal affinity chromatography (IMAC) provides strong antibacterial activity against Candida albicans. The synergistic effect of siderophores and amphotericin B was also demonstrated. Our results have shown that the GZDF3 strain could produce a large amount of siderophores with strong antagonistic activity, which is helpful in the development of new biological control agents.