• 한국미생물·생명공학회지
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• 제23권5호
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• pp.536-543
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• 1995

Multicopy integration vector is a very useful vector system in that they can be integrated into chromosomal DNA in several copies and stably maintained under non-selective conditions. To develop a multicopy integration vector system in the yeast Yarrowia lipolytica, P-type ribosomal DNA was cloned from Y lipolytica. A HindIII-BglII fragment of the cloned rDNA and a promoterless URA3 gene were inserted into pGEM1, generating multicopy integration vectors, pMIYL-1 and pMIYL-2. The rDNA fragment is for targeted homologous recombination between the vector and the chromosomal DNA of Y. lipolytica, and the promoterless URA3 gene is a defective selection marker for inducing multicopy integration. pMIYL-1 and pMIYL-2 have an unique restriction enzyme site, KpnI, and two unique restriction enzyme sites, KpnI and EcoRI, repectively, which can be used for targeting of the vectors into the rDNA of Y. lipolytica chromosomal DNA. After transformation of the vectors into Y. lipolytica, copy number and stability were analyzed by Southern hybridization. The vectors were found to be present in less than 5 copies per cell and were stably maintained during growth in non-selective media.

• 전기전자학회논문지
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• 제7권1호
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• pp.97-106
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• 2003

ARQ 기반의 오류 제어에서 불완전한 오류 검출로 인해 패킷에 오류가 잔류하게 된다. 본 논문에서는 사본 중복 전송 ARQ에서 잔류 오류를 감소시키기 위한 재전송 요청 및 오류없는 사본의 결정 규칙을 제안한다. 이러한 $(m, \;{\sigma})$ 규칙을 사본 중복 전송 ARQ에 적용할 때, 잔류 오류는 감소하나 기존의 단일 사본만을 전송하는 ARQ에 비해 지연 및 throughput 성능은 열화될 수 있다. 따라서 $(m, \;{\sigma})$ 규칙이 적용된 사본 중복 전송 ARQ에서 야기되는 성능의 trade-off를 평가하기 위한 해석적 방법을 개발한다. 이러한 해석적 방법으로 구한 계량적 결과로부터 $(m, \;{\sigma})$ 규칙의 파라미터, 채널의 성질, 트래픽 부하가 오류 잔류 확률, 패킷 상실, 패킷 지연, throughput 등에 미치는 영향을 검토하여 다양한 QoS 요구 조건을 용이하게 수용할 수 있는 $(m, \;{\sigma})$ 규칙의 적응성을 확인한다.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.334-337
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• 2008

A tightly regulated gene expression system composed of a single-copy target gene under the control of a lac promoter derivative and lacI gene in a multicopy plasmid is proposed, and its ability to control the flux of a metabolic pathway is demonstrated. A model system to control the flux of acetyl-CoA to acetyl phosphate was constructed by integrating pta, a gene encoding phosphotransacetylase, under a tac promoter into the chromosome of E. coli with a pta-negative background and transforming a multicopy plasmid containing the $lacI^Q$ gene into the strain. The production rate of acetate was shown to be tightly controlled when varying the concentration of the inducer (IPTG) in he model system.

• Genomics & Informatics
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• 제14권1호
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• pp.29-33
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• 2016

A retron is a bacterial retroelement that encodes an RNA gene and a reverse transcriptase (RT). The former, once transcribed, works as a template primer for reverse transcription by the latter. The resulting DNA is covalently linked to the upstream part of the RNA; this chimera is called multicopy single-stranded DNA (msDNA), which is extrachromosomal DNA found in many bacterial species. Based on the conserved features in the eight known msDNA sequences, we developed a detection method and applied it to scan National Center for Biotechnology Information (NCBI) RefSeq bacterial genome sequences. Among 16,844 bacterial sequences possessing a retron-type RT domain, we identified 48 unique types of msDNA. Currently, the biological role of msDNA is not well understood. Our work will be a useful tool in studying the distribution, evolution, and physiological role of msDNA.

• 미생물학회지
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• 제27권2호
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• pp.92-97
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• 1989

the vector, pGUR19, for Rhizobium gene manipulation, was constructed by combining the replication and mobilization function of indigenous multicopy plasmid from Acacia(Robinia pseudoacacia L.) Rhizobia sp86 with E. coli cloning vehicle, pBR322. The vector could be efficiently mobilized by RP4 tra function incorporated into chromosome of E. coli named SM10 and efficiently transferred to various gram negative hosts including Rhizobium and Afrobacterium by transformation. Mobilization frequency of the constructed vector was ranged from $1.2\times 10^{-2}$ (E.coli HB 101) to $4.6\times 10^{-4}$ (A. tumefaciens 15955) and transformation frequency was ranged from $5.4\times 10^{-7}$(E. coli HB101) to $1.2\times 10^{-10}$ (A. tumefaciens 15955). The vector, pGUR19, was stably replicated and maintained in a variety of Rhizobium and Agrobacterium.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.319-322
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• 2002

In this paper, we consider a generalized rule of retransmission request, identified as (Μ, $\sigma$) rule for multicopy transmission ARQ. Following a revised rule to conform with a strict criterion for requesting a retransmission, we can reduce the probability that a packet accepted by the receiving node is still being infected with errors. In turn, such amendment invokes a degradation of delay and throughput performance. For a quantitative evaluation of (Μ, $\sigma$) rule, we develop an analytical method to calculate probability of error remains, maximum throughput, average and peak delays, and delay variation. From the numerical examples made by use of the analytical method, we observe a performance trade-off between probability of error remains and delay/throughput. We also confirm the adaptability of (Μ, $\sigma$) rule to meet various QoS requirements.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.321-321
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• 1995

• BMB Reports
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• 제29권3호
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• pp.221-224
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• 1996

To examine the growth-phase dependent control of Escherichia coli rnpB gene we used a combination of Northern analysis for RNA determination and Southern analysis for plasmid DNA determination. The relative amounts of metabolically unstable transcript derived from the internally deleted rnpB gene harbored on a multicopy plasmid as well as the relative plasmid contents were measured by Northern analysis and Southern analysis, respectively, of total nucleic acids from E coli cells containing the plasmid. The relative transcription activity of the rnB was represented by a ratio of the relative amount of the transcript to that of the plasmid DNA during bacterial growth. The rnpB transcription increased rapidly with time during exponential growth, but started to decrease before the transition period of an exponential growing cell culture into the stationary phase. Although the expression pattern was similar to the changes of ${\beta}-galactosidase$ activity expressed from the lysogenic strain carrying the chromosomal rnpB-lacZ fusion which were shown in a previous work, the present data appears to represent a more actual growth-phase control of the rnpB transcription than the previous data by the ${\beta}-galactosidase$ assay. In addition the present method described for a direct analysis of both RNA and plasmid DNA provides a rapid and efficient method that can applied to an examination of transcription control by using a multicopy plasmid.

• 미생물학회지
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• 제28권1호
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• pp.35-40
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• 1990

Thiostrepton 내성 유전자(tsr)를 포함하는 multi-copy 재조합 플라스미드 pJY7J2의 제한효소 절단지도를 작성하였다. pJY, 712는 Streptomyces에서 넓은 host range를 나타내었으며 cloning 목적에 사용할 수 있는 단일 BgtIl 제한효소 인식부위를 갖고 있었다. 플라스미드 pJY 712는 lethal zygosis(Ltz+) 현상을 보였다. pJY 712의 혁질전환빈도는 S. lividans에서 $5.0\times 10^{4}$ TFU였다. pJY 712의 Bell 제한효소 인식부위에 tyrosmase 유전자(mel)를 삽입하여 플라스미드 PJY713을 제조하였다. met 유전자를 포함한 재조합 플라스미드 pJY 714는 pJY 713의 일부분(1.9kb BgllI-BelI 단편)을 제거하여 제고하였다.

• Journal of Life Science
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• 제9권1호
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• pp.54-57
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• 1999

We have got several clones from Serratia marcescens which stimulated the cells to use maltose as a carbon source in E. coli TP2139 (${\Delta}$lac, ${\Delta}$crp). One of the cloned genes, pCKB13, was further analyzed. In order to find whether the increased expression of the gene under the direction of maltose metabolism, we constructed several recombinant subclones. We have confirmed that the clone, pCKB13 codes Coenzyme A transferase gene by partial nucleotide sequencing in the terminal region. The enzyme activity of Coenzyme A transferase increased after introduction of the multicopy of the cloned gene in E. coli. The recombinant proteins expressed by multicopy and induction with IPTG, two polypeptide of 26-and 28-kDa, were confirmed by SDS-PAGE. Southern hybridization analysis confirmed that the cloned DNA fragment was originated from S. marcescens chromosomal DNA.