• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.112-116
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• 2021

The aim of this study is to analyze the complementizer that-deletion in embedded complement clauses in English. This paper is concerned with the alternation between the overt that-complementizer and the zero complementizer by the complementizer deletion (C-deletion or that-deletion) in constructions with a nominal complement that-clause, i.e. [VP Verb [CP that-TP]]. In this paper, we compare that-complementation and zero-complementation in a diachronic grammaticalization and corpus, and show that the complementizer that has its origin in pronouns diachronically and finally becomes to form a C-head of the functional category CP. We provide the syntactic and semantic explanation on the optionality of that-deletion while answering the question why and how that-deletion is getting increasing in use especially with the verb, think, in the informal contexts. With the major causes for the currently increasing use of that-deletion, we are concerned with the contexts in which the overt complementizers or the covert complementizers are preferred.

• 대한바이러스학회지
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• 제30권3호
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• pp.161-170
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• 2000

Continuous efforts are being made to find effective therapeutic agents against HIV-1, the causative agents of AIDS. In this study, we developed a cell-based assay system employing a trans-complementation for production of recombinant viruses which are capable of undergoing one round of replication in CD4+ T cells. This assay system was tested for ability to screen the agents that act at late stage of HIV-1 life cycle. The effect of a protease inhibitor on the trans-complementation assay was assessed. Recombinant HIV-1 viruses were prepared from a trans-complementation in the presence of various concentrations of protease inhibitor. Inhibition of single round infection of these recombinant viruses by protease inhibitor was observed to be a dose-dependent manner. Inhibitory effects of a protease inhibitor on HIV-1 Gag polyprotein processing by HIV-1 protease was detected at concentrations of the protease inhibitor compatible with inhibition of virus infection, confirming that the corresponding step was involved in the inhibitory mechanism of this compound. Together, these results provide evidence that a cell-based assay system established in this study can be used to screen the agents that target the late stage of HIV-1 life cycle.

• BMB Reports
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• 제46권1호
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• pp.53-58
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• 2013

We constructed deletion mutants and seven point mutants by polymerase chain reaction to investigate the specificity of feline foamy virus integrase functional domains. Complementation reactions were performed for three enzymatic activities such as 3'-end processing, strand transfer, and disintegration. The complementation reactions with deletion mutants showed several activities for 3'-end processing and strand transfer. The conserved central domain and the combination of the N-terminal or C-terminal domains increased disintegration activity significantly. In the complementation reactions between deletion and point mutants, the combination between D107V and deletion mutants revealed 3'-end processing activities, but the combination with others did not have any activity, including strand transfer activities. Disintegration activity increased evenly, except the combination with glutamic acid 200. These results suggest that an intact central domain mediates enzymatic activities but fails to show these activities in the absence of the N-terminal or C-terminal domains.

• 한국동물생명공학회지
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• 제38권1호
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• pp.2-9
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• 2023

Mammalian eyes have a limited ability to regenerate once neurons degenerate. This results in visual impairment that impacts the quality of life among adult populations as well as in young children leading to lifelong consequences. Various therapies are in development to restore vision, and these include gene therapy, stem cell therapy, in-vivo transdifferentiation, and transplantation of a patient's whole eye obtained from interspecies blastocyst complementation. This review discusses advances in the research as well as hurdles that need to be resolved to have a successful restoration of vision.

• Molecules and Cells
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• 제27권1호
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• pp.83-88
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• 2009

Amino acid homology analysis predicted that rbmD, a putative glycosyltransferase from Streptomyces ribosidificus ATCC 21294, has the highest homology with neoD in neomycin biosynthesis. S. fradiae BS1, in which the production of neomycin was abolished, was generated by disruption of the neoD gene in the neomycin producer S. fradiae. The restoration of neomycin by self complementation suggested that there was no polar effect in the mutant. In addition, S. fradiae BS6 was created with complementation by rbmD in S. fradiae BS1, and secondary metabolite analysis by ESI/MS, LC/MS and MS/MS showed the restoration of neomycin production in S. fradiae BS6. These gene inactivation and complementation studies suggested that, like neoD, rbmD functions as a 2-N-acetlyglucosaminyltransferase and demonstrated the potential for the generation of novel aminoglycoside antibiotics using glycosyltransferases in vivo.

• Journal of Microbiology and Biotechnology
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• 제26권1호
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• pp.66-71
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• 2016

PikD is a widely known pathway-specific regulator for controlling pikromycin production in Streptomyces venezuelae ATCC 15439, which is a representative of the large ATP-binding regulator of the LuxR family (LAL) in Streptomyces sp. RapH and FkbN also belong to the LAL family of transcriptional regulators, which show greatest homology with the ATP-binding motif and helix-turn-helix DNA-binding motif of PikD. Overexpression of pikD and heterologous expression of rapH and fkbN led to enhanced production of pikromycin by approximately 1.8-, 1.6-, and 1.6-fold in S. venezuelae, respectively. Cross-complementation of rapH and fkbN in the pikD deletion mutant (ΔpikD) restored pikromycin and derived macrolactone production. Overall, these results show that heterologous expression of rapH and fkbN leads to the overproduction of pikromycin and its congeners from the pikromycin biosynthetic pathway in S. venezuelae, and they have the same functionality as the pathwayspecific transcriptional activator for the pikromycin biosynthetic pathway in the ΔpikD strain. These results also show extensive "cross-communication" between pathway-specific regulators of streptomycetes and suggest revision of the current paradigm for pathwayspecific versus global regulation of secondary metabolism in Streptomyces species.

• 미생물학회지
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• 제27권2호
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• pp.77-84
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• 1989

Saccharomyces cerevisiae의 RNAI 유전자의 온도 감수성 돌연변이 균주는 성장허용 온도인 23"C에서는 정상적인 성"J--을하나, 성 장억제 온도인 36°C에서는 tRNA, rRNA 그러고 mRNA 의 선우울질을을 핵내에 축적함으후써 성장을 못한다. 본 실 험에서는 complementation 에 의하여 RNAI 유전자를 클로녕하였으며 concomitant loss 실험에 의하여 이 유천자의 클로닝 을 확인하였다. 유전자의 위치를 확인한 결과 3.5kb의 Bgl II 조각내에 RNAI 유전자가 존재함을 알 수 있였으며, 2.1kb에 해당하는 BamH I -Bgl II 조각에서는 RNAI 유전지에 의한 complementation 능력이 상실되는 것으후 보아 RNAI 유전자 는 3.5kb의 BglIl 조각내에 포함되는 BamH 1 자리 주위에 결쳐 있픔을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.250-256
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• 1995

The ddh gene encoding meso-diaminopimelate (meso-DAP)-dehydrogenase (DDH) in Brevibacterium lactofermentum was isolated by complementation of the Escherichia coli dapD mutation. It was supposed from subcloning experiments and complementation tests that the evidence for DDH activity appeared in about 2.5 kb Xhol fragmented genome. The 2.5 kb Xhol fragment containing the ddh gene was sequenced, and an open reading frame of 960 bp encoding a polypeptide comprising 320 amino acids was found. Computer analysis indicated that the deduced amino acid of the B. lactofermentum ddh gene showed a high homology with that of the Corynebacterium glutamicum ddh gene.

• 한국식품영양과학회지
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• 제30권5호
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• pp.802-805
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• 2001

산업적으로 lysine 발효 산업에 이용되고 있는 B. lactofermentum으로부터 lysine 생합성에 관여하는 tetrahyrodipicolinate N-succinyl transferase를 지령하는 dapD 유전자를 E. coli의 dapD 결손변이주와의 complementation test를 통하여 cloning하였다. 재조합 plamid는 3.6 kb의 DNA 단편을 함유하고 있었으며 Southern blot hybridization을 통하여 dapD 유전자는 B. lactofermentum으로부터 유래하였으며 염색체 DNA내에 single copy로 존재함을 알 수 있었다. 또한 lysine 생성량 분석을 통하여 E. coli에서 B. lactofermentum dapD 유전자의 발현을 확인하였다.

• 미생물학회지
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• 제54권4호
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• pp.309-319
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• 2018

이전의 연구에서 질소원이 존재하여도 페로몬을 유도하는 6개의 Schizosaccharomyces pombe 돌연변이체를 온도민감성 돌연변이체들의 저장고로부터 분리하였음이 보고된 바 있다. 본 연구에서는 이들 중 하나인 pws6 돌연변이체의 특성을 더 연구하였다. 이 돌연변이체는 영양물질에 특이적으로 페로몬 유도를 나타내었다. 즉 질소의 고갈은 없어도 M-factor 페로몬을 유도하였으나 탄소의 고갈이 없으면 유도되지 않았다. 이러한 결과는 pws6 돌연변이체가 질소 고갈을 전달하는 경로에 특이한 결함을 가지고 있음을 시사한다. 이 돌연변이체는 M-factor 페로몬뿐만 아니라 P-factor 페로몬도 온도에 민감한 양식으로 질소의 고갈 없이 유도함을 보여 주어 이 돌연변이체의 페로몬 유도는 세포 유형에 특이적이지 않음을 시사하였다. 이 돌연변이체의 온도 민감성 성장 결함의 상보적 보완에 의해 $pws6^+$ 유전자를 클로닝하여 8.1 kb, 3.3 kb, 그리고 4.8 kb 효모 DNA를 가진 3개의 플라스미드가 분리되었다. 이 플라스미드들은 pws6 돌연변이체의 성장 결함을 각각 100%, 70%, 그리고 10-20% 보완하였다. 또한 이 플라스미드들은 pws6 돌연변이체의 페로몬 유도 특성을 보완하는 능력을 가지고 있었으며 이는 돌연변이체의 성장 결함 보완 효율과 밀접한 연관성이 있음을 보여 주었다. 이들의 오픈 리딩 프레임을 성장 결함의 보완 효율과 비교하여 오픈 리딩 프레임 SPBC19C7.06이 pws6 돌연변이체의 온도 민감성 특성을 상보적으로 보완하는데 원인이 되는 리딩 프레임으로 결론 내렸다. 이 오픈 리딩 프레임은 prs1으로 명명되었으며 인트론이 없이 하나의 긴 엑손을 가지고 있는 추정된 prolyl tRNA synthetase를 암호화한다. 추정된 Prs1 단백질은 다른 종의 prolyl tRNA synthetase와 상당한 유사성을 보여 주었다.