• Journal of Microbiology
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• 제37권4호
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• pp.224-228
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• 1999

Benzaldehyde dehydrogenase (BZDH), an enzyme involved in the degradation of toluene and xylenes, is encoded by the phnN gene of Pseudomonas sp. strain DJ77. We determined the nucleotide sequence of a DNA fragment of 1,803 base pairs which included the phnN gene. The fragment contained an open reading frame of 1,506 base pairs to accommodate th 55 kDa sized enzyme encoding BZDH. The enzyme efficiently oxidized benzaldehyde, salicylaldehyde, m-tolualdehyde and ps-tolualdehyde.

• 치과방사선
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• 제29권1호
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• pp.299-308
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• 1999

Purpose: The purpose of this study was to compare the qualities of the four different processing chemicals (solutions). Materials and Methods: With EP 21 films(Ektaspeed plus film, Kodak Co., USA), nine unexposed and nine exposed films of a step wedge were processed utilizing automatic film processor(XR 24, Durr Co., Germany) for 5 days. During 5 days, the total number of processed films including out-patient' s intraoral films were about 400-500 for each brand. Base plus fog density, film density, contrast of processed films were measured with densitometer(model 07-443 digital densitometer, Victoreen Co., USA). These measurements were analyzed for comparison. Results: The results were as follows, 1. For the base plus fog density. there was significant difference among the four chemicals (p<0.05). The sequence of the base plus fog densities was in ascending order by Kodak, X-dol 90. Agfa and Konica. 2. For the film density. all chemicals showed useful range of photographic densities(0.25-2.5). The sequence of the film densities was in ascending order by Kodak, X-dol 90, Konica and Agfa. But there was no statistically significant difference of film density between X-dol and Kodak (p<0.05). 3. The sequence of the contrasts was in ascending order by Konica, X-dol 90, Kodak and Agfa. But there was no statistically significant difference of contrast between X-dol and Konica (p<0.05). Conclusion: These results indicated that the four processing chemicals had clinically useful film density and contrast. but only Kodak processing chemical had useful base plus fog density.

• 대한수학회지
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• 제47권4호
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• pp.861-877
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• 2010

The works of Erd$\ddot{o}$s et al. about expansions of 1 with respect to a non-integer base q, referred to as q-expansions, are investigated to determine how far they continue to hold when the number 1 is replaced by a positive number x. It is found that most results about q-expansions for real numbers greater than or equal to 1 are in somewhat opposite direction to those for real numbers less than or equal to 1. The situation when a real number has a unique q-expansion, and when it has exactly two q-expansions are studied. The smallest base number q yielding a unique q-expansion is determined and a particular sequence is shown, in certain sense, to be the smallest sequence whose corresponding base number q yields exactly two q-expansions.

• 한국통신학회논문지
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• 제22권7호
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• pp.1505-1514
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• 1997

In this paper, a temporally adaptive layered image sequence coding technique employing H.261 is proposed. In the proposed technique, the frame rate of the base layer is adjusted according to the temporal activity measure based on the rate-distortion function. The base layer is encoded using the H.261. Then, the full frame-rate error image is formed by comparing the original image and the interpolated version of the reconstructed base layer image. The enhancement layer is algo encoded using H.261 but with leaky prdiction to provide robust error resilience. The simulation results show that the proposed technique provides better performance than the twin-H.261 with leaky prediction in both the fixed-rate and variable-rate systems.

• 한국자기공명학회논문지
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• 제17권2호
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• pp.76-80
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• 2013

The TCP domain is a DNA-binding domain present in plant transcription factors and has a similar structural feature to the bHTH motif of eukaryotic transcription factors. The imino proton exchange study has been performed for the DNA duplex containing the consensus DNA-binding site for the AtTCP11 transcription factor. The first two base pairs in the consensus 5'-GTGGG-3' sequence are relatively very unstable but lead to greater stabilization of the neighboring two G C base pairs. These unique dynamic features of the five base pairs in the consensus DNA sequence might play crucial roles in the effective DNA binding of the AtTCP11 protein.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1583-1591
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• 2020

CRISPR/Cpf1 has emerged as a new CRISPR-based genome editing tool because, in comparison with CRIPSR/Cas9, it has a different T-rich PAM sequence to expand the target DNA sequence. Single-base editing in the microbial genome can be facilitated by oligonucleotide-directed mutagenesis (ODM) followed by negative selection with the CRISPR/Cpf1 system. However, single point mutations aided by Cpf1 negative selection have been rarely reported in Corynebacterium glutamicum. This study aimed to introduce an amber stop codon in crtEb encoding lycopene hydratase, through ODM and Cpf1-mediated negative selection; deficiency of this enzyme causes pink coloration due to lycopene accumulation in C. glutamicum. Consequently, on using double-, triple-, and quadruple-base-mutagenic oligonucleotides, 91.5-95.3% pink cells were obtained among the total live C. glutamicum cells. However, among the negatively selected live cells, 0.6% pink cells were obtained using single-base-mutagenic oligonucleotides, indicating that very few single-base mutations were introduced, possibly owing to mismatch tolerance. This led to the consideration of various target-mismatched crRNAs to prevent the death of single-base-edited cells. Consequently, we obtained 99.7% pink colonies after CRISPR/Cpf1-mediated negative selection using an appropriate single-mismatched crRNA. Furthermore, Sanger sequencing revealed that single-base mutations were successfully edited in the 99.7% of pink cells, while only two of nine among 0.6% of pink cells were correctly edited. The results indicate that the target-mismatched Cpf1 negative selection can assist in efficient and accurate single-base genome editing methods in C. glutamicum.

• 정보처리학회논문지A
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• 제9A권3호
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• pp.387-398
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• 2002

최근 활발한 소단위 게놈 프로젝트의 수행으로 많은 생물체의 유전체 전체 서열이 밝혀짐에 따라서 전유전체(whole genome)를 기본 단위로 하여 개별 유전자나 그에 관련된 기능 연구가 매우 활발히 이루어지고 있다. 전유전체의 염기 서열은 수백만 bp(base pairs)에서 수백억 bp(base pairs) 정도의 대용량 텍스트 데이터이기 때문에 단순한 온라인 문자 일치(on-line string matching) 알고리즘으로 분석하는 것은 매우 비효율적이다. 본 논문에서는 대용량의 유전체 서열을 분석하는데 적합한 자료 구조인 스트링 B-트리를 사용하여 유전체 서열의 분석과 가시화를 위한 워크벤치를 개발한 과정을 소개한다. 본 연구에서 개발한 시스템은 크게 질의문 부분과 가시화 부분으로 나뉘어 진다. 질의문 부분에는 유전체 서열에 특정 서열이 나타나는 부분의 위치와 횟수를 알아보거나 k번 나타나는 서열을 조사하는 것과 같은 기본적인 패턴 검색 부분과 k-mer 분석을 위한 질의어가 다양하게 준비되어 있다. 가시화 부분은 전유전체 서열과 주석(annotation)을 보여주거나, 유전체 분석을 용이하도록 여러 가시화 방법, CGR(Chaos Game Representation), k-mer graph, RWP(Random Walk Plot) 등으로 생물학자들이 쉽게 전체 구조와 특성 파악할 수 있도록 도와준다. 본 논문이 제안하는 분석 시스템은 생물체의 진화적 관계를 밝히고, 염색체 내에 아직 알려지지 않은 새로운 유전자나 기능이 밝혀지지 않은 junk DNA들의 기능 등을 연구하는데 사용할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.139-145
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• 1993

The nucleotide sequence of the xylanase gene (xynS) from alkali-tolerant Bacillus sp. YA.14 was determined and analyzed. A 639 base pairs open reading frame for xynS gene was observed and encoded for a protein of 213 amino acids with a molecular weight of 23, 339. S1 nuclease mapping showed that the transcription initiation site of the xynS gene did not exist in the cloned DNA. Ribosome binding site sequence with the free energy of -18.8 Kcal/mol was observed 8 base pairs upstream from the initiation codon, ATG. The proposed signal sequence consisted of 28 amino acids, of which 3 were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YA-14 xylanase showed 48% homology with Bacillus sp. YC-335 xylanase and 96% homology with xylanases from B. subtilis and B. circulans.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.224-231
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• 1993

The nucleotide sequence of the xylanase gene (xynY) from alkalophilic Bacillus sp. YC-335 was determined and analyzed. An open reading frame of 1, 062 base pairs for xynY gene was observed and encoded for a protein of 354 amino acids with a molecular weight of 38, 915. S1 nuclease mapping showed that the transcription initiation sites of the xynY gene were different in Bacillus sp. YC-335 and Escherichia coli HB101 (pYS55). S1 mapping also showed that -10 region of the xynY gene recognized by RNA polymerases of E. coli and Bacillus sp. YC-335 were TACAGT and TATGAT , respectively. A ribosome binding site sequence with the free energy of -17.0 Kcal/mol was observed 9 base pairs upstream from the unusual initiation codon, TTG. The proposed signal sequence consisted of 27 amino acids, 2 of which were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YC-335 xylanase showed more than 50% homology with xylanases from B. pumilus, B. subtilis, and B. circulans.

• 미생물학회지
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• 제36권3호
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• pp.192-195
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• 2000

백색부후균류 laccase의 아미노 말단과 카복시 말단에 잘 보존된 구리결합부위를 암 호화하는 DNA 염기서열과 상보적인 primer를 이용하여 백색부후균의 일종인 영지버섯 Gandoderma lucidum에서 laccase 유전자 단편을 분리하였다. PCR 로 증폭하여 클로닝한 1.6 Kb DNA 절편의 염기 서열을 결정하여 분석하였다. 이 DNA에는 7개의 인트론이 존재 하였으며 엑손의 염기서열과 이로부터 추정된 아미노산 서열은 Tranmetes villosa laccase(lccl)와 각각 47%, 79% 동일하였다. 기타 다른 백색부후균류의 laccase 아미노산 서 열과는 66~78% 동일하였다.