• BMB Reports
• /
• v.29 no.3
• /
• pp.183-191
• /
• 1996

DNA fragments, homologous to the dTDP-D-glucose 4,6-dehydratase gene, obtained from the genomic DNA of Streptomyces antibioticus $T\ddot{u}99$, a producer of the unusual macrolide antibiotic chlorothricin, were cloned and sequenced. This dehydratase gene was designated as oxil. The coding region of the oxil gene is composed of 987 bp, and analysis of the DNA sequence data reveals sequences for the gene products of 329 amino acids (molecular weight of 36,037). The deduced amino acids are 59% identical to the StrE, dTDP-D-glucose 4,6-dehydratase from the streptomycin pathway. The oxil's function was examined by expressing it in E. coli using the T7 RNA polymerase/promoter system (pRSET) to produce an active fusion protein including a his tag. This enzyme shows specificity of substrate, specific only to dTDP-D-glucose.

• Animal Systematics, Evolution and Diversity
• /
• v.32 no.4
• /
• pp.258-265
• /
• 2016

Acrobeloides nanus (de Man, 1880) Anderson, 1968 belonging to the family Cephalobidae Filpijev, 1934 (Cephalobomorpha) is newly reported from South Korea. This species is distinguished from other Acrobeloides species by its low and blunt labial probolae, five lateral incisures with middle incisure extending to the tail tip, and bluntly rounded tail. In this study, details of morphological characters of A. nanus is described and illustrated based on optical and scanning electron microscopy. In addition, molecular sequence data of the D2-D3 region of 28S rDNA, 18S rDNA and mitochondria DNA cox1 region from this species are provided as DNA barcode sequences.

• ALGAE
• /
• v.27 no.3
• /
• pp.175-187
• /
• 2012

Hainan is the second largest and southernmost island of China, and it harbors many species of the family Gracilariaceae. In this study, we conducted molecular and morphological analyses of gracilarian specimens collected from Hainan Island, to clarify their taxonomic identity and phylogenetic relationships. Five species of Gracilariaceae in Hainan were determined through maximum likelihood and Bayesian analysis of rbcL sequence data. Based on the phylogenetic trees and morphology, Hainan specimens were identified as three species of Gracilaria, one species of Gracilariopsis, and one species of Hydropuntia, namely, G. salicornia, G. tenuistipitata, Gracilaria sp., Gp. bailiniae and H. edulis. This is the first report of the molecular phylogeny of Gracilariaceae on Hainan Island, and it helps to clarify the taxonomy and distribution of gracilarian species in the Asia-Pacific region.

• Fisheries and Aquatic Sciences
• /
• v.12 no.1
• /
• pp.35-43
• /
• 2009

Sturgeons and paddlefishes are frequently referred to as 'living fossils' among the actionpterygian lineage. They are increasingly facing threats to their existence because of various anthropogenic pressures. In this study, we present the complete mitogenome sequence of the Russian sturgeon Acipenser gueldenstaedtii (Acipenseriformes; Acipenseridae). The mitogenome showed highly homogeneous molecular features compared to previously known vertebrate mitogenomes. Phylogenetic tree inferred from concatenated protein-coding and tRNA genes unambiguously revealed the monophyly of A. gueldenstaedtii, Acipenser stellatus, and Huso huso. Genetic information of the endangered A. gueldenstaedtii will provide baseline data needed to develop molecular markers for stock identification and assessment of population diversity and also to develop future conservation strategies.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.5
• /
• pp.327-331
• /
• 2000

The application of LFH-PCR(long flanking homology region-PCR) for Bacillus subtilis gene disruption is presented. Without plasmid- or phage-vector construction, only by PCR, based on a DNA sequence retrieved from B. subtilis genome data base, kanamycin resistance gene was inserted into two genes of B. subtilis involved in sporulation, spoIIIE and spoIIIG. The effect of gene disruption on subtilisin expression was examined and the sporulation frequency of two mutants was compared to that of the host strain. For this purpose, only 2 or 3 rounds of PCR were required with 4 primers. We first demonstrated the possibility of LFH-PCR for rapid gene disruption to characterize an unknown functional gene of B. subtilis or other prokaryote in the genomic era.

• The Korean Journal of Zoology
• /
• v.37 no.3
• /
• pp.343-351
• /
• 1994

The partial nucleotide sequences of 185 ribosomal RNA gene were compared for six cnidarian species (one belongs to class Hvdrozoa: Coryne pusilla. Five belong to class Anthozoa: Beflonella rigida from Octocorallia; Anemonia sulcutu, Anthopfeura kurognne, An thopleura midori from Hexacorallia: Cerianthus filiformis from Ceriantipatharial. The aligned sequence data were used to test the hypothesis on the anthozoan phylosenv by using the distance matrix method and parsimony method. The phvlosenetic inferences resulting from these methods indicate that the anthozoan is a monophvletic group and support the three subclass scheme (Octocorallia, HexBcorallia, Ceriantipatharial within class Anthozoa. The result also indicates that ceriantipatharian is more primitive than the other groups and that family Actiniidae is a monophvletic group within the anthozoan. However, the present analysis does not clearly indicate the phvlogenetic relationships of species among genera.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.4
• /
• pp.492-495
• /
• 2015

This study provides evidence that RecG regulates the expression of the OxyR-independent gene mexA in Pseudomonas aeruginosa PAO1. A reduction in mexA expression was observed in the absence of RecG, but not OxyR, by northern blot and quantitative real-time PCR analyses. The canonical palindromic RecG binding sequence was present upstream of the mexA promoter, and bound purified RecG and single strand-binding protein. These data reveal a novel mechanism of OxyR-independent gene transcription by RecG.

• Proceedings of the Botanical Society of Korea Conference
• /
• 1987.07a
• /
• pp.323-347
• /
• 1987

The R locus of maize in one of several genes that regulate the anthocyanin pigments throughout the body of the plant and seed. The R gene product may regulate pigment deposition by controlling the expression of the flavonoid biosynthetic gene pathway in a tissue-specific manner. To understand the basis for tissue specific regulation and allelic variation at R, the molecular study has been done by cloning a portion of the R complex by transposon tagging with Ac. R specific probe were cloned from the R-nj mutant induced by Ac insertion mutagenesis. From southern analysis of R-r complex using the R-nj probe, the structure of R-r was proposed that R-r containes the three elements, (P)(Q)(S). These elements may organize as the inversion triplication model which (S) sequence was inverted in relation to (P) and (Q). The R-sc derivated from R-mb or R-nj was cloned with R-nj probe, and molecular genetical data showed that R-sc containes tissue specific and tissue nonspecific area, and the sequencing of R-sc are progressed now.

• Biomolecules & Therapeutics
• /
• v.17 no.2
• /
• pp.151-155
• /
• 2009

Hepatitis C virus (HCV) has genetic diversity like most of RNA viruses. HCV major genotypes are classified into several subtypes which are further divided into quasispecies having, genetically different but closely related variants. The HCV core that is a nucleocapsid protein located at the amino terminus of the viral polyprotein is relatively a conserved protein among the HCV isolates and thus it has been one of plausible targets for anti-HCV drug development. However, different quasispecies of HCV core gene have also been found. In this study, we compared the expression level of core protein between two different quasispecies of HCV genotype 1b. Our data demonstrate that a little differences of amino acid sequence lead to substantial difference of expression level. It might be another important reason of different pathogenesis among HCV infected patients.

• Research in Plant Disease
• /
• v.28 no.2
• /
• pp.57-60
• /
• 2022

Leaves of Chionanthus retusus were found to be damaged by leaf spot disease associated with a fungus in Iksan, Korea. Leaf spots were angular to irregular, vein-limited, scattered, 1-8 mm diameter, brownish-gray to dark brown when dry, with heavy fructification. The pathogen causes premature defoliation of C. retusus plant and was identified as Pseudocercospora chionanthi-retusi based on morphological and molecular-phylogenetic analyses. The phylogenetic tree was constructed using multi-locus DNA sequence data of partial actin (actA), partial translation elongation factor 1-alfa (tef1), partial DNA-directed RNA polymerase II second largest subunit (rpb2) genes, and internal transcribed spacer regions. Current study provides detail morphological description of P. chionanthi-retusi on C. retusus in Korea, with supports of phylogenetic analysis and pathogenicity test.