• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1454-1459
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• 2013

The changes in prodiginines productions caused by pH shock culture of Streptomyces coelicolor strains were estimated. In Streptomyces coelicolor M511, undecylprodiginine and streptorubin B productions increased 1.8-fold (37.22 mg/g) and 2.5-fold (18.61 mg/g), respectively, by pH shock (from 7.2 to 4.0). In contrast, this resulted in the significantly decreased prodigignines production in the redP deletion mutant SJM1; 3.7-fold for undecylprodiginine, 4.4-fold for streptorubin B, 5.2-fold for methylundecylprodiginine, and 6.4-fold for methyldodecylundecylprodiginine, respectively. RT-PCR analyses showed that, during pH shock, expression of redD, the transcription activator gene, was increased while the expression of fabH, the decarboxylative condensation enzyme gene in fatty acid biosynthesis, was decreased in both strains. The enhanced redD expression was in good accordance with the increased total prodiginines production of M511. However, for SJM1 mutant, the decrease of fabH expression occurred more strikingly, such that it became almost completely turned off during acidic pH shock culture. Therefore, a down-regulation of fabH was considered to be the cause of decreased amount of total prodiginines produced, although redD expression was high in SJM1 mutant.

• Journal of Microbiology
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• v.44 no.1
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• pp.121-125
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• 2006

Mycothiol is a low molecular weight thiol compound produced by a number of actinomycetes, and has been suggested to serve both anti-oxidative and detoxifying roles. To investigate the metabolism and the role of mycothiol in Streptomyces coelicolor, the biosynthetic genes (mshA, B, C, and D) were predicted based on sequence homology with the mycobacterial genes and confirmed experimentally. Disruption of the mshA, C, and D genes by PCR targeting mutagenesis resulted in no synthesis of mycothiol, whereas the mshB mutation reduced its level to about $10\%$ of the wild type. The results indicate that the mshA, C, and D genes encode non-redundant biosynthetic enzymes, whereas the enzymatic activity of MshB (acetylase) is shared by at least one other gene product, most likely the mca gene product (amidase).

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.81-86
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• 2004

Among the annotated ORFs of Streptomyces coelicolor, SCO7697 was supposed to encode for phytase (myo-inositol hexakisphosphate phosphohydrolase). The DNA fragment containing SCO7697 was cloned by the PCR from the chromosomal DNA of S.coelicolor A3(2)M. The cloned fragment was introduced into E. coli expres-sion vector, pET28a(+), to yield two recombinant plasmids, pET28-SP and pET28-LP, which were designed to encode different length of proteins. When the pET28-SP and pET28-LP were introduced into E. coli BL21, the transformants successfully overexpressed recombinant proteins, but the molecular weights of the expressed pro-teins were appeared bigger than those of expected in SDS-polyacrylamide gel electrophoresis. The shift of cul-tural temperature from 37 to $30^{\circ}C$ made most of expressed protein be solubilized. The expressed protein, however, did not show any phytase activity. When the DNA fragment with its own promoter placed on the E. coli-Streptomyces vector, pWHM3, and introduced into S. lividans, the phytase activity was not detected either. These results suggest that even though the SCO7697 was annotated as a probable phytase with high probability (E value is $6e^{-89}$), the real product doest not have phytase activity.

• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.55-55
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• 2002

An alternative sigma factor as encoded by the $\sigma$$\^$B/ gene in Streptomyces coelicolor A3(2) was known to be involved in the differentiation and osmotic stress response. Protein expression profiles of wild-type and a $\sigma$$\^$B/ mutant strain of S coelicolor A3(2), which is impaired in defense against osmotic stress, were compared in the absence and presence of osmotic stress, using 2-dimentional gel electrophoresis.(omitted)

• Journal of Microbiology
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• v.42 no.2
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• pp.147-151
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• 2004

$\sigma^{B}$ plays an important role in both osmoprotection and proper differentiation in Streptomyces coelicolor A3(2). We searched for candidate members of the $\sigma^{B}$ regulon from the genome database, using the consensus promoter sequence (GNNTN$_{14-16}$GGGTAC/T). The list consists of l15 genes, and includes all the known $\sigma^{B}$ target genes and many other genes whose functions are related to stress protection and dif-ferentiation.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.756-763
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• 2021

Agarose is a linear polysaccharide composed of ᴅ-galactose and 3,6-anhydro-ʟ-galactose (AHG). It is a major component of the red algal cell wall and is gaining attention as an abundant marine biomass. However, the inability to ferment AHG is considered an obstacle in the large-scale use of agarose and could be addressed by understanding AHG catabolism in agarolytic microorganisms. Since AHG catabolism was uniquely confirmed in Vibrio sp. EJY3, a gram-negative marine bacterial species, we investigated AHG metabolism in Streptomyces coelicolor A3(2), an agarolytic gram-positive soil bacterium. Based on genomic data, the SCO3486 protein (492 amino acids) and the SCO3480 protein (361 amino acids) of S. coelicolor A3(2) showed identity with H2IFE7.1 (40% identity) encoding AHG dehydrogenase and H2IFX0.1 (42% identity) encoding 3,6-anhydro-ʟ-galactonate cycloisomerase, respectively, which are involved in the initial catabolism of AHG in Vibrio sp. EJY3. Thin layer chromatography and mass spectrometry of the bioconversion products catalyzed by recombinant SCO3486 and SCO3480 proteins, revealed that SCO3486 is an AHG dehydrogenase that oxidizes AHG to 3,6-anhydro-ʟ-galactonate, and SCO3480 is a 3,6-anhydro-ʟ-galactonate cycloisomerase that converts 3,6-anhydro-ʟ-galactonate to 2-keto-3-deoxygalactonate. SCO3486 showed maximum activity at pH 6.0 at 50℃, increased activity in the presence of iron ions, and activity against various aldehyde substrates, which is quite distinct from AHG-specific H2IFE7.1 in Vibrio sp. EJY3. Therefore, the catabolic pathway of AHG seems to be similar in most agar-degrading microorganisms, but the enzymes involved appear to be very diverse.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.7-14
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• 1997

This study was to elucidate the relation between the periodical requirement of growth factors(Yang et al., 1993) and the synthesis of RNA and protein during the germination of Streptomycn coefic%r A3(2) in mineral liquid medium(ISP-4) without addition of growth factors. As results, The germination time was about 10 hr, and meanwhile, periodical nutritional requirement was verified to be repeated with interval of 2 hr. Spore size was enlarged with time but its number was rather decreased. Spore could be deviJed into viable, dormant, and dead state. In such a germination process it was found that RNA and protein were being synthesized periodically when spores were stained with AO and INT methods and observed under the fluorescence microscope. Those syntheses were coincided with the period of nutritional requirement. Hence, it was discllssed that spore population in early germination would need amino acids related to protein synthesis.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.243-248
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• 2016

RNase E (Rne) is an essential enzyme involved in the processing and degradation of a large portion of RNAs in Escherichia coli. The enzymatic activity of RNase E is controlled by regulators of ribonuclease activity, namely, RraA and RraB. Gram-positive bacterium Streptomyces coelicolor also contains homologs of Rne and RraA, designated as RNase ES (Rns), RraAS1, and RraAS2. In the present study, we investigated the effect of S. coelicolor RraAS1 on the ribonucleolytic activity of RNase E in E. coli. Coexpression of RraAS1 with Rne resulted in the decreased levels of rpsO, ftsZ, and rnhB mRNAs, which are RNase E substrates, and augmented the toxic effect of Rne overexpression on cell growth. These in vivo effects appeared to be induced by the binding of RraAS1 to Rne, as indicated by the results of co-immunoprecipitation analysis. These results suggested that RraAS1 induces ribonucleolytic activity of RNase E in E. coli.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.295.2-295
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• 1995

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.294.2-294
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• 1995

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