• Title/Summary/Keyword: Conserved motifs

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Secondary Structure and Phylogenetic Implications of ITS2 in the Genus Tricholoma

  • Suh, Seok-Jong;Kim, Jong-Guk
    • Journal of Microbiology and Biotechnology
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    • v.12 no.1
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    • pp.130-136
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    • 2002
  • The internal transcribed spacer (ITS) region in the genus Tricholoma was analyzed, including for its primary nucleotide sequence and secondary structural characterization. The secondary structures of the ITS2 region in the genus Tricholoma were identified for use in bioinformatic processes to study molecular evolution and compare secondary structures. Ten newly sequenced ITS regions were added to the analysis and submitted to the GenBank database. The resulting structure from a minimum energy algorithm indicated the four-domain model, as previously suggested by others. The conserved secondary structure of the ITS2 sequences of the genus Tricholoma exhibited certain unique features, including pyrimidine tracts in the loops of domain A and a complete structure containing four domains, with motifs identified in other ITS2 secondary structures. A phylogenetic tree was derived from sequence alignment based on the secondary structures. From the resulting maximum parsimonious tree, it was found that the species in the genus Tricholoma had evolved monophyletically and were composed of four groups, as supported by the bootstrapping values and pileus color.

Identification and Heterologous Expression of a ${\Delta}4$-Fatty Acid Desaturase Gene from Isochrysis sphaerica

  • Guo, Bing;Jiang, Mulan;Wan, Xia;Gong, Yangmin;Liang, Zhuo;Hu, Chuanjiong
    • Journal of Microbiology and Biotechnology
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    • v.23 no.10
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    • pp.1413-1421
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    • 2013
  • The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, $C20:5{\omega}-3$) and docosahexaenoic acid (DHA, $C22:6{\omega}-3$) that are important to human health. Here, we report a functional characterization of a ${\Delta}4$-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.

Molecular Cloning and Characterization of cDNA Encoding Farnesyl Diphosphate Synthase in Garlic (Allium sativum) (마늘의 Farnesyl Diphosphate Synthase 유전자 클로닝 및 분자생물학적 특성규명)

  • Pham, Anh Tuan;Park, Nam-Il;Kim, Haeng-Hoon;Park, Sang-Un
    • Korean Journal of Agricultural Science
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    • v.37 no.3
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    • pp.367-371
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    • 2010
  • Farnesyl diphosphate synthase (FPS) catalyzes the biosynthesis of farnesyl diphosphate, a precursor for many important terpenoid products. A cDNA encoding FPS was first isolated from Allium sativum (AsFPS) using rapid amplification of cDNA ends (RACE) PCR. The sequence of AsFPS contains an open reading frame encoding a protein of 341 amino acids with a predicted molecular mass of 39.61 kDa. Alignment of AsFPS deduced amino acid revealed high identities with other plants ranging from 79% to 85% and showed 2-high conserved aspartate-rich motifs known to be important for FPS activity. Furthermore, AsFPS expression was stronger in the green organs such as bulbils, scapes, leaves, stems, but weaker in bulbs and roots than on-green organs of A. sativum.

Molecular Characterization of a Chinese cabbage cDNA, C-DH, Predominantly Induced by Water-Deficit Stress and Plant Hormone, ABA (수분부족 및 식물호르몬, ABA에 의하여 발현이 유도되는 배추의 C-DH cDNA에 대한 분자적 특성)

  • 정나은;이균오;홍창휘;정배교;박정동;이상열
    • Korean Journal Plant Pathology
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    • v.14 no.3
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    • pp.240-246
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    • 1998
  • A cDNA encoding desiccation-related protein was isolated from a flower bud cDNA library of Chinese cabbage (C-DH) and its nucleotide sequence was characterized. It contains 679 bp nucleotides with 501 bp open reading frame. The amino acid sequence of the putative protein showed the highest amino acid sequence homology (79 % identity) to dehydrin protein in Gossypium hirsutum. Also, the C-DH shares 48-52% amino acid sequence identity with the other typical dehydrin proteins in plant cells. When the amino acid sequence of their proteins were aligned, several peptide motifs were well conserved, of which function has to be solved. Particularly the C-DH contains 15 additional amino acids at its N-terminus. Genomic Southern blot analysis using the coding region of C-DH showed that the C-DH consists of a single copy gene in Chinese cabbage genome. The C-DH mRNA, whose transcript size is 0.7 kb, was expressed with a tissue-specific manner. It was highly expressed in seed, flower buds and low expression as detected in root, stem or leaf tissues of Chinese cabbage. And the transcript level of C-DH was significantly induced by the treatment of plant hormone, abscisic acid and water-deficit conditions.

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VaSpoU1 (SpoU gene) may be involved in organelle rRNA/tRNA modification in Viscum album

  • Ahn, Joon-Woo;Kim, Suk-Weon;Liu, Jang-Ryol;Jeong, Won-Joong
    • Plant Biotechnology Reports
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    • v.5 no.3
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    • pp.289-295
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    • 2011
  • The SpoU family of proteins catalyzes the methylation of transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs). We characterized a putative tRNA/rRNA methyltransferase, VaSpoU1 of the SpoU family, from Viscum album (mistletoe). VaSpoU1 and other plant SpoU1s exhibit motifs of the SpoU methylase domain that are conserved with bacterial and yeast SpoU methyltransferases. VaSpoU1 transcripts were detected in the leaves and stems of V. album. VaSpoU1-GFP fusion proteins localized to both chloroplasts and mitochondria in Arabidopsis protoplasts. Sequence analysis similarly predicted that the plant SpoU1 proteins would localize to chloroplasts and mitochondria. Interestingly, mitochondrial localization of VaSpoU1 was inhibited by the deletion of a putative N-terminal presequence in Arabidopsis protoplasts. Therefore, VaSpoU1 may be involved in tRNA and/or rRNA methylation in both chloroplasts and mitochondria.

Molecular Characterization of a Novel Putative Partitivirus Infecting Cytospora sacchari, a Plant Pathogenic Fungus

  • Peyambari, Mahtab;Habibi, Mina Koohi;Fotouhifar, Khalil-Berdi;Dizadji, Akbar;Roossinck, Marilyn J.
    • The Plant Pathology Journal
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    • v.30 no.2
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    • pp.151-158
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    • 2014
  • Three double-stranded RNAs (dsRNAs), approximately 1.85, 1.65 and 1.27 kb in size, were detected in an isolate of Cytospora sacchari from Iran. Partial nucleotide sequence revealed a 1,284 bp segment containing one ORF that potentially encodes a 405 aa protein. This protein contains conserved motifs related to RNA dependent RNA polymerases (RdRp) that showed similarity to RdRps of partitiviruses. The results indicate that these dsRNAs represent a novel Partitivirus that we tentatively designate Cytospora sacchari partitivirus (CsPV). Treatment of the fungal strain by cyclohexamide and also hyphal tip culture had no effect on removing the putative virus. Phylogenetic analysis of putative RdRp of CsPV and other partitiviruses places CsPV as a member of the genus Partitivirus in the family Partitiviridae, and clustering with Aspergillus ochraceous virus 1.

Analysis of the Complete Genome Sequence of Zucchini yellow mosaic virus strain A Isolated from Hollyhock

  • Choi, Seung-Kook;Yoon, Ju-Yeon;Sohn, Seong-Han
    • The Plant Pathology Journal
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    • v.23 no.4
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    • pp.245-250
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    • 2007
  • The complete genome sequence of Zucchini yellow mosaic virus stain A (ZYMV-A) isolated from a hollyhock (Althaea rosea) was determined by using RT-PCR with a series of primer sets. The virus genome consisted of 9593 nucleotides (nt), excluding the poly(A) tract at 3' terminus of the virus genome, with 5' and 3' untranslated region of 139 and 211 nt, respectively. The deduced polyprotein of ZYMV-A consisted of 3080 amino acid (aa) residues and was 351 kDa in molecular weight. All proteolytic cleavage sites of the polyprotein of ZYMV-A were compared with those of ZYMV strains, which showed the cleavage sites were conserved among ZYMV strains. The HC-Pro contained the KITC and PTK motifs, and the DAG motif was located at CP ORF of ZYMV-A, suggesting that ZYMV-A is aphid-transmissible. Phylogenetic tree analysis based on the complete genome among ZYMV strains or CP ORFs with other potyviruses showed ZYMV strains formed a distinct group. These results clearly confirmed that ZYMV-A was another distinct strain in ZYMV population at molecular level.

Human Caliciviruses in Korea: A New Prevalent Group Defined by RNA-Dependent RNA Polymerase Diversity (한국형 사람 Caliciviruses의 RNA-Dependent RNA Polymerase Diversity)

  • Han, Dong-Pyo;Kim, Ji-Aee;Yang, Jai-Myung;Kim, Kyung-Hee
    • The Journal of Korean Society of Virology
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    • v.27 no.1
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    • pp.1-8
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    • 1997
  • Human caliciviruses (HuCVs) cause sporadic cases and outbreaks of acute gastroenteritis (AGE). Three major genogroups of HuCVs have been described including the Norwalk virus (NV)-, the Snow Mountain virus (SMA)-, and the Sapporo-genogroups. This study describes the detection and genetic variation of HuCVs from hospitalized infants with AGE in Korea by RT-PCR and sequencing. The cDNA fragments of 206 to 470bp corresponding to the region of 3 primer pairs (36/35, 35/51 or 3/51) in the polymerase region of NV were generated. Of 185 stools screened, 8% were positive by RT-PCR and their sequences showed that all strains contained the GLPSG and YGDD motifs which are conserved for HuCVs. Amino acid (aa) sequence analysis showed that these strains can be divided into 3 major genogroups. High conservation was observed in that one strain shares 100% of aa sequence with Southampton virus, another shares 99% with the Sapporo virus, and six strains share 90 to 95% with Snow Mountain virus. However, significant sequence variation was also found in other strains. This study indicates that all major genogroups of HuCVs are circulating in Korea.

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Nucleotide Sequence of 7.2 kb Mitochondrial Linear Plasmid DNA in Pleurotus ostreatus (Pleurotus ostreatus 미토콘드리아의 7.2 kb 선상 플라스미드 염기서열 분석)

  • 윤혜숙;구용범;노정혜
    • Korean Journal of Microbiology
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    • v.37 no.1
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    • pp.37-41
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    • 2001
  • Two linear plasmid-like DNAs, 10.2 kb and 7.2 kb were found in the mitochondria of P. ostreatus. They have covalently linked 5'-terminal proteins in both ends. Two continuous fragments of 4.7 kb and 2.3 kb from 7.2 kb DNA were cloned and sequenced. Two long open reading frames (ORF1; 2982 bp, 993 a.a and ORF2; 2703 bp, 900 a.a) and one short open reading frame(ORF3; 771 bp, 256 a.a) were found in the 7.2 kb plasmid. The putative ORF1 and ORF2 have conserved motifs of DNA polymerases and RNA polymerases, respectively, while the ORF3 has homologous regions with phosphatase from Plasmodium, and also with adhesine from Mycoplasma.

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Structural Characteristics of Two Wheat Histone H2A Genes Encoding Distinct Types of Variants and Functional Differences in Their Promoter Activity

  • Huh, Gyung-Hye;Iwabuchi, Masaki
    • Proceedings of the Botanical Society of Korea Conference
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    • 1996.07a
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    • pp.26-38
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    • 1996
  • To investigate the regulation of plant histone H2A gene expression, we isolated two H2A genes (TH254 and TH274) from wheat, which encode different types of variants. Both genes had an intron in the coding region. In the promoters, some characteristics sequences, such as Oct and Nona motifs, which are conserved among plant histone genes were also found, and they were located in a short region (about 120 bp) upstream from the putative TATA box. Analyses of promoter activity with H2A-GUS fusion genes in the transient system using tobacco protoplasts revealed novel types of positive cis-acting sequences in the TH254 promoter: a direct repeat of a 13-bp sequence (AGTTACATTATTG) and a stretch composed of an AT-rich sequence (ATATAGAAAATTAAAA) and a G-box (CACGTG). A quantitative S1 assay of the mRNA amounts from the TH254/GUS and TH274/GUG chimeric genes in stably transformed and cell cycle-synchronized tobacco cell lines showed that the promoters of both genes contained at least one cis-acting element responsible for S phase-specific expression. Histochemical analysis of transgenic tobacco plants carrying the chimeric genes showed that the promoters of the two H2A genes were both active in developing seedlings and flower organs but regulated in different manner.

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