• Interdisciplinary Bio Central
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• 제3권4호
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• pp.14.1-14.9
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• 2011

Protein homology detection is an important issue in comparative genomics. Because of the exponential growth of sequence databases, fast and efficient homology detection tools are urgently needed. Currently, for homology detection, sequence comparison methods using local alignment such as BLAST are generally used as they give a reasonable measure for sequence similarity. However, these methods have drawbacks in offering overall sequence similarity, especially in dealing with eukaryotic genomes that often contain many insertions and duplications on sequences. Also these methods do not provide the explicit models for speciation, thus it is difficult to interpret their similarity measure into homology detection. Here, we present a novel method based on Word Conservation Score (WCS) to address the current limitations of homology detection. Instead of counting each amino acid, we adopted the concept of 'Word' to compare sequences. WCS measures overall sequence similarity by comparing word contents, which is much faster than BLAST comparisons. Furthermore, evolutionary distance between homologous sequences could be measured by WCS. Therefore, we expect that sequence comparison with WCS is useful for the multiple-species-comparisons of large genomes. In the performance comparisons on protein structural classifications, our method showed a considerable improvement over BLAST. Our method found bigger micro-syntenic blocks which consist of orthologs with conserved gene order. By testing on various datasets, we showed that WCS gives faster and better overall similarity measure compared to BLAST.

• 미생물학회지
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• 제38권4호
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• pp.267-275
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• 2002

미생물 유전체 프로젝트의 결과인 유전체 서열에 대해, 비교 유전체 분석을 수행할 수 있는 분석 도구인 GComp를 개발하였다. 이 도구는 국부 상동성 계산을 BLAST나 FASTA를 사용하여 수행한 후에 그 결과를 받아들여, 상동성을 보이는 부분을 분석하고 위치 파악 및 연결한 뒤, 두 유전체간의 상동성 정도를 일목요연하게 보여줄 수 있는 테이블과 파일들을 생성한다. 한편. 그 결과를 그래픽으로 표시하고 전체를 살펴볼 수 있는 인터페이스 기능을 구현하였다. 시험 데이터로 기존의 미생물 유전체 서열을 상대로 분석하면서, 유전체 서열의 핵산 및 단백질 수준에서의 비교분석 결과를 통해 두 유전체에 대한 비교 정보를 효과적으로 확인할 수 있었고, 보다 다양한 분석을 위한 도구 개발의 기준을 설정할 수 있었다.

• 미생물학회지
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• 제29권5호
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• pp.284-289
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• 1991

the nucleotide sequence of the 3' terminal 568 bases of the 18S rRNA gene from Mucor racemosus was determined. The 3' end of the structural gene was identified by comparison with the published sequence for the Saccharomyces cerevisiae gene. The M. racemosus gene was found to share 83.8% homology with that of S. cerevisiae and 71-81% homology with those of human, mouse, maize, Xenopus laevis and Tetrahymena thermophila. The known methylation sites in X. laevis and human were also highly conserved in M. racemosus and located within most conserved regions of 18S RNA gene throughout evolution.

• Journal of Plant Biotechnology
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• 제3권3호
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• pp.131-134
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• 2001

In $\lambda$-Zap II vector system, a cDNA library was constructed for the developing secondary xylem mRNA from hybrid poplar, Populus nigra x maximowiczii. A cDNA clone of 1.5 kb in size, pOMTB1.4 encoding a lignin-bispecific O-methyltransferase was screened by plaque hybridization using a probe of 540 bp cDNA amplified by polymerase chain reaction from the cDNA library and identified by nucleotide sequencing. Its nucleotide sequence contains one open reading frame of 366 amino acids. The deduced amino acid sequence in comparison with that of Populus tremuloides showed the differences of 9 amino acids and revealed 85-99% homology among alfalfa, poplar and aspen.

• Genomics & Informatics
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• 제9권2호
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• pp.79-84
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• 2011

Two initial models of cold-adapted lipase PsLip1 have been constructed, based on homology with the bacterial lipases Chromobacterium viscosum (CvLip) and Pseudomonas cepacia (PcLip), whose X-ray structures have been solved and refined to high resolution. The mature polypeptide chains of these lipases have 84% similarity. The models of Mod1 and Mod2 have been compared with the tertiary structures of CvLip and PcLip, respectively, and analyzed in terms of stabilizing interactions. Several structural aspects that are believed to contribute to protein stability have been compared: the number of conserved salt bridges, aromatic interactions, hydrogen bonds, helix capping, and disulfide bridges. The 3-dimensional structural model of PsLip1 has been constructed in order to elucidate the structural reasons for the decreased thermostability of the enzyme in comparison with its mesophilic counterparts.

• BMB Reports
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• 제39권5호
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• pp.578-585
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• 2006

The cDNA of a firefly luciferase from lantern mRNA of Lampyroidea maculata has been cloned, sequenced and functionally expressed. The cDNA has an open reading frame of 1647 bp and codes for a 548-residue-long polypeptide. Noteworthy, sequence comparison as well as homology modeling showed the highest degree of similarity with H. unmunsana and L. mingrelica luciferases, suggesting a close phylogenetic relationship despite the geographical distance separation. The deduced amino acid sequence of the luciferase gene of firefly L. maculata showed 93% identity to H. unmunsana. Superposition of the three-dimensional model of L. maculata luciferase (generated by homology modeling) and three dimensional structure of Photinus pyralis luciferase revealed that the spatial arrangements of Luciferin and ATP-binding residues are very similar. Putative signature of AMP-binding domain among the various firefly species and Lampyroidea maculata was compared and a striking similarity was found. Different motifs and sites have been identified in Lampyroidea maculata by sequence analysis. Expression and purification of luciferase from Lampyroidea maculata was carried out using Ni-NTA Sepharose. Bioluminescence emission spectrum was similar to Photinus pyralis luciferase.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1816-1821
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• 2003

Reliable PCR based identification of lactobacilli has been described utilizing the sequence of 16S-23S rRNA intergenic spacer region. Those sequence comparisons showed a high degree of difference in homology among the strains of L. rhamnosus, L. casei, L. acidophilus and L. helveticus whose 16S-23S rRNA intergenic small SR's sizes were 222 bp, 222 bp, 206 bp and 216 bp respectively. The sequence of 16S-23S rRNA intergenic spacer region of L. rhamnosus ATCC 53103 revealed the close relatedness to those of L. casei strains by the homology ranges from 95.4% to 97.2%. 16S-23S rRNA intergenic spacer region nucleotide sequence of L. acidophilus showed some distant relatedness with L. rhamnosus ATCC 53103 with the homology ranges from 40.3% to 41.8% and that with L. helveticus was shown to be 30% of homology, which exists at the most distant phylogenetic relatedness. The identification of species and strain of lactobacilli was possible on the basis of these results. The common sequences among the 17 strains were CTAAGGAA located in the initiating position of the DNA and some discrepancies were found between the same strains based on these results.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.195.1-195
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• 1996

No Abstract, See Full Text

• Parasites, Hosts and Diseases
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• 제35권2호
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• pp.105-110
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• 1997

T. sergenti 국내 분리주의 면역항원인 33 kDa의 piroplasm surface protein 유전자를 크로닝하였다. 크로닝된 T. sergenti의 33 kDa에 해당하는 유전자의 염기서열을 분석한 결과 총 869 bps의 염기와 283개의 아미노산을 확인하였다. 또 이들 분석결과를 일본주의 염기서열 및 아미노산 조성과 비교 분석하였던 바 각각 99.4. 98.9%의 homology를 나타내었으므로 두 주간의 p33 유전자는 거의 일치하는 것으로 판명되었다.

• 한국식물병리학회지
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• 제11권1호
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• pp.73-79
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• 1995

Complementary DNAs (cDNAs) to the coat protein gene of an ordinary Korean strain of potato virus Y (PVY-OK) isolated from potato (cv. Superior) were synthesized and cloned into a plasmid pUC119 and sequenced. The RNA of the virus propagated in tobacco (Nicotinaa sylvestris) was extracted by the method of phenol extraction. The first strand of cDNAs to the coat protein penomic RNA of the virus was made by Moloney murine leukemia virus reverse transcriptase. The cDNA were synthesized and amplified by the method of polymerase chain reaction (PCR) using a pair of oligonucleotide primers. PVYCP3P and PVYCP3M. The size of cDNAs inserted in pUC119 plasmid was estimated as about 840 bp upon agarose gel electrophoresis. Double stranded cDNAs were transformed into the competent cell of E. coli JM109. Sequence analysis of cDNAs was conducted by the dideoxynucleotide chain termination method. Homology of cDNAs of the PVY-OK coat protein genomic RNA with those of PVY-O (Japan), PVY-T (Japan), PVY-TH (Japan), PVYN (The Netherlands),and PVYY (France) was represented as 97.3%, 88.9%, 89.3%, 89.6% and 98.5%, respectively. Homology at the amino acid level turned out to the be 97.4%, 92.5%, 92.9%, 92.9% and 98.5%, respectively.