• Journal of Life Science
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• v.9 no.3
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• pp.262-267
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• 1999

Mitochondrial DNA (mtDNA) polymorphism of the blue mussel (Mytilus edulis) species complex sampled from the east coast of Korean was studied using a partial sequence of COIII gene (336 bp). Samples obtained from three localities on the east coast of Korea revealed four haplotypes with two clearly differentiated mitochondrial clades (termed clades B and E), separated by 4.2% of minimum sequence divergence. This pattern indicates no difference between east and south coasts of Korea. According to population genetic theory on evolutionary characteristics of mtDNA, we concluded that mtDNA introgression from M. edulis to M. gallprovincialis might be a source for mtDNA polymorphism found in mussels on the east coast of Korea.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.666-670
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• 2021

Paenibacillus konkukensis sp. nov., SK3146 is a novel strain isolated from a pig feed. Here, we present complete genome sequence of SK3146. The genome consists of a single circular genome measuring 7,968,964 bp in size with an average guanine + cytosine (G+C) content of 53.4%. Genomic annotation revealed that the strain encodes 151 proteins related to hydrolases (EC3), which was higher than those in Bacillus subtilis and Escherichia coli. Diverse kinds of hydrolases including galactosidase, glucosidase, cellulase, lipase, xylanase, and protease were found in the genome of SK3146, coupled with one bacteriocin encoding gene. The complete genome sequence of P. konkukensis SK3146 indicates the immense probiotic potential of the strain with nutrient digestibility and antimicrobial activity functions.

• Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.191-196
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• 2021

A single specimen of Liparis punctulatus (30.9 mm standard length) belonging to the family Liparidae, was collected in the waters off Busan on 4 August, 2016. This species is characterized by a single pair of nostrils, unlike other Liparis species. It is distinguished from L. ochotensis by the numbers of dorsal, anal, pectoral fin rays and the location of the gill opening (above the pectoral fin in L. punctulatus vs. extending ventrally in front of the pectoral fin). In the molecular analysis, 514 bp of 16S rRNA gene of the specimen in this study were identical to that of L. punctulatus from NCBI GenBank (K2P distance < 0.002). This is the first record of the species in Korea based on a voucher specimen, and we follow the Korean name "Kko-ma-kkom-chi" for this species proposed by Myoung et al. and Kim et al.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.562-565
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• 2023

Escherichia coli-specific phage, KFS-EC1, was isolated and purified from a slaughterhouse. The complete genome of the phage was obtained using Illumina MiSeq platforms. Its assembled genome consisted of a single chromosome of 164,715 bp with a GC content of 40.5%. The phage genome contained 170 hypothetical and 101 functional ORFs, and exhibited orthologous average nucleotide identity values of >95% with other E. coli phages belonging to the family Straboviridae. Additionally, phylogenetic analysis revealed that KFS-EC1 was finally classified into the family Straboviridae of the genus Caudoviricetes. The genome has been deposited in GenBank under the accession number NC_055757.1.

• Journal of Life Science
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• v.6 no.4
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• pp.234-240
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• 1996

A double-stranded RNA binding factor (RBF), characterized as an inhibitor of PKR kinase in our previous study, was evaluated for its RNA binding specificities by RNA gel electrophoretic mobility shift analysis and membrane filter binding assay, RBF displayed affinities for a broad range of RNAs including viral RNAs and synthetic RNAs consiting of stem and loop structures. GC-rich RNA stem helices as short as 11 bp are suggested to represent the minimal binding motif for RBF. RBF binding to all the natural RNAs tested was reversible by poly(I): poly(C) addition, but E. coli 5S RNA was inefficient.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.511-518
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• 2006

A gene cluster for cyclohexanone oxidation was cloned from Rhodococcus sp. TK6, which is capable of growth on cyclohexanone as the sole carbon source. The 9,185-bp DNA sequence analysis revealed seven potential open reading frames (ORFs), designated as ssd-chnR-chnD-chnC-chnB-chnE-partial pcd. The chnBCDE genes encode enzymes for the four-step conversion of cyclohexanone to adipic acid, catalyzed by cyclohexanone monooxygenase (ChnB), $\varepsilon-caprolactone$ hydrolase (ChnC), 6-hydroxyhexanoate dehydrogenase (ChnD), and 6-oxohexanoate dehydrogenase (ChnE). Furthermore, the presence of a regulatory element in the downstream region of the chnD gene supports the notion that chnR is a putative regulatory gene. Among them, the activity of ChnB was confirmed and characterized, following their expression and purification in Escherichia coli harboring the modified chnB gene (chnB gene with 6 successive codons for His at the 3' terminus).

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.786-796
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• 1999

As an attempt to develop an effective control method against theileriosis, recombinant antigen protein was produced. Thirty-two kDa membrane protein(MP) gene of T sergenti was amplified through RT-PCR from extracted total RNA of T sergenti isolated in Chonbuk, Korea. The amplified 869 bp of Korean T sergenti membrane gene was cloned and the base sequences were analyzed. The amplified gene was cloned into E coli expression vector, pQE32 plasmid vector, and the vector was introduced into E coli strain M15 to produce the recombinant membrane protein. For the induction of T sergenti membrane protein(KTs-MP), the plasmid harboring E coli strain M15 were cultured in the presence of IPTG, and the recombinant protein were purified by $Ni^+$-NTA agarose. Then, to confirm the authenticity of the produced membrane protein, molecular weight of expressed recombinant KTs-MP was analyzed by SDS-PAGE and Western blotting. The molecular weight of expressed recombinant protein was 32 kDa as expected. The recombinant KTs-MP was successfully recognized by anti-His Tag antibody, antisera of T sergenti infected cattle and monoclonal antibody of T sergenti membrane protein. Therefore, we concluded that the authentic 32 kDa membrane protein of T sergenti was produced as immunologically recognizable form.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.299-304
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• 2008

A ${\beta}$-1,4-endoglucanase gene from Bacillus subtilis H12 was cloned into Escherichia coli JM109 (pBC8) and sequenced. The endoglucanase gene with an insert DNA of 2.5 kb possessed an open reading frame of 1,500 bp encoding a mature protein of 499 amino acids with a calculated molecular mass of 55 kDa. The deduced amino acid sequence showed similarity to those of the known neutral cellulase genes of B. subtilis PAP115 (99.2%) and BSE616 (97.8%), as well as the alkaline gene of Bacillus sp. N4 (55.1%). The endoglucanase activity expressed by E. coli (pBC8) was localized in the periplasmic fraction (80%) and the cytoplasmic fraction (20%). An endoglucanase was purified from the periplasmic fraction by performing gel filtration and anion exchange chromatography. The molecular weight of the purified enzyme was estimated to be 31 kDa by SDS-PAGE, and the maximum activity occurred at pH 7 and $40^{\circ}C$. The enzyme easily hydrolyzed soluble substrates such as carboxymethyl cellulose and barely ${\beta}$-glucan, whereas the sigmacell and xylan, the known insoluble substrates, were not entirely hydrolyzed.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.619-622
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• 2006

Biotransformation is a good tool to synthesize regioselective compounds. It could be performed with diverse sources of genes, and microorganisms provide a myriad of gene sources for biotransformation. We were interested in modification of flavonoids, and therefore, we cloned a putative O-methyltransferase from Bacillus cereus, BcOMT-2. It has a 668-bp open reading frame that encodes a 24.6-kDa protein. In order to investigate the modification reaction mediated by BcOMT-2, it was expressed in E. coli as a His-tag fusion protein and purified to homogeneity. Several substrates such as naringenin, luteolin, kaempferol, and quercetin were tested and reaction products were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). BcOMT-2 could transfer a methyl group to substrates that have a 3' functional hydroxyl group, such as luteolin and quercetin. Comparison of the HPLC retention time and UV spectrum of the quercetin reaction product with corresponding authentic 3'-methylated and 4'-methylated compounds showed that the methylation position was at either the 3'-hydroxyl or 4'-hydroxyl group. Thus, BcOMT-2 transfers a methyl group either to the 3'-hydroxyl or 4'-hydroxyl group of flavonoids when both hydroxyl groups are available. Among several flavonoids that contain a 3'- and 4'-hydroxyl group, fisetin was the best substrate for the BcOMT-2.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1583-1590
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• 2006

T4 endonuclease V (T4 endo V) [EC 3. 1. 25. 1], found in bacteriophage T4, is responsible for excision repair of damaged DNA. The enzyme possesses two activities: a cyclobutane pyrimidine dimer DNA glycosylase (CPD glycosylase) and an apyrimidic/apurinic endonuclease (AP lyase). T4 denV (414 bp cDNA) encoding T4 en do V (138 amino acid) was synthesized and expressed using either an expression vector, pTriEx-4, in E. coli or a baculovirus AcNPV vector, pBacPAK8, in insect cells. The recombinant His-Tag/T4 endo V (rHis-Tag/T4 endo V) protein expressed from bacteria was purified using one-step affinity chromatography with a HiTrap Chelating HP column and used to make rabbit anti-His-Tag/T4 endo V polyclonal antibody for detection of recombinant T4 endo V (rT4 endo V) expressed in insect cells. In the meantime, the recombinant baculovirus was obtained by cotransfection of BacPAK6 viral DNA and pBP/T4 endo V in Spodoptera frugiperda (Sf21) insect cells, and used to infect Sf21 cells to overexpress T4 endo V protein. The level of rT4 endo V protein expressed in Sf21 cells was optimized by varying the virus titers and time course of infection. The optimal expression condition was set as follows; infection of the cells at a MOI of 10 and harvest at 96 h post-infection. Under these conditions, we estimated the amount of rT4 endo V produced in the baculovirus expression vector system to be 125 mg/l. The rT4 endo V was purified to homogeneity by a rapid procedure, consisting of ion-exchange, affinity, and reversed phase chromatographies, based on FPLC. The rT4 endo V positively reacted to an antiserum made against rHis-Tag/T4 endo V and showed a residual nicking activity against CPD-containing DNA caused by UV. This is the first report to have T4 endo V expressed in an insect system to exclude the toxic effect of a bacterial expression system, retaining enzymatic activity.