• BMB Reports
• /
• v.46 no.1
• /
• pp.53-58
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.5
• /
• pp.1063-1066
• /
• 2004

The rpoS gene product is a global transcriptional factor, which is involved in bacterial survival under various stress conditions. An rpoS-homologous gene was cloned from a septicemia-causing pathogenic Vibrio vulnificus. Introduction of this gene as a multicopy plasmid into various E. coli strains displayed functional complementation, for examples, increased survivability of an rpoS-defective E. coli cell and induction of known $\delta^S$-dependent, stress-responding promoters of E. coli genes.

• International Journal of Advanced Culture Technology
• /
• v.9 no.3
• /
• pp.112-116
• /
• 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.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2005.05a
• /
• pp.218.1-218
• /
• 2005

• Proceedings of the Zoological Society Korea Conference
• /
• 1999.10b
• /
• pp.278.1-278
• /
• 1999

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
• /
• v.21 no.1
• /
• pp.14-19
• /
• 2011

A cyclic undecapeptide-family natural product, cyclosporin A (CyA), which is one of the most valuable immunosuppressive drugs, is produced nonribosomally by a multifunctional cyclosporin synthetase enzyme complex in a filamentous fungal strain named Tolypocladium niveum. Previously, structural modifications of cyclosporins such as a regionspecific hydroxylation at the $4^{th}$ N-methyl leucine in a rare actinomycetes called Sebekia benihana were reported to lead to dramatic changes in their bioactive spectra. However, the reason behind this change could not be determined since a system to genetically manipulate S. benihana has not yet been developed. To address this limitation, in this study, we utilized the most commonly practiced gene manipulation techniques including conjugation-based foreign gene transfer-and-expression as well as targeted gene disruption to genetically manipulate S. benihana. Using these optimized genetic manipulation systems, a putative cytochrome P450 hydroxylase (CYP) gene named CYP506, which is involved in CyA hydroxylation in S. benihana, was specifically disrupted and genetically complemented. The S. benihana${\Delta}$CYP506 exhibited a significantly reduced CyA hydroxylation yield as well as considerable yield restoration by functional complementation of the S. benihana CYP506 gene, suggesting that the genetically manipulated S. benihana CYP mutant strains may serve as a more efficient bioconversion host for various valuable metabolites including CyA.

• Journal of Life Science
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2013

Understanding salt tolerance mechanisms is important for the increase of crop yields, and so, several screening approaches were developed to identify plant genes which are involved in salt tolerance of plants. Here, we transformed the Arabidopsis cDNA library into a salt-sensitive calcineurin (CaN)-deficient ($cnb{\Delta}$) yeast mutant and isolated the colonies which can suppress salt-sensitive phenotype of $cnb{\Delta}$ mutant. Through this functional complementation screen, a total of 34 colonies functionally suppressed the salt-sensitive phenotype of $cnb{\Delta}$ yeast cells, and sequencing analysis revealed that these are 9 genes, including CaS, AtSUMO1 and AtHB-12. Among these genes, the ectopic expression of CaS gene increased salt tolerance in yeast, and CaS transcript was up-regulated under high salinity conditions. CaS-antisense transgenic plants showed reduced root elongation under 100 mM NaCl treatment compared to the wild type plant, which survived under 150 mM NaCl treatment, whereas CaS-antisense transgenic plant leaves turned yellow under 150 mM NaCl treatment. These results indicate that the expression of CaS gene is important for stress tolerance in yeast and plants.

• Molecules and Cells
• /
• v.23 no.3
• /
• pp.405-409
• /
• 2007

A putative type-I chalcone isomerase (CHI) cDNA clone EuNOD-CHI was previously isolated from the root nodule of Elaeagnus umbellata [Kim et al. (2003)]. To see if it encodes a functional CHI, we ectopically overexpressed it in the Arabidopsis (Arabidopsis thaliana) transparent testa 5 (tt5) mutant, which is defective in naringenin production and has yellow seeds due to proanthocyanidin deficiency. Ectopic overexpression of EuNOD-CHI resulted in recovery of normal seed coat color. Naringenin produced by CHI from naringenin chalcone was detected in the transgenic lines like in the wild-type, whereas it was absent from the tt5 mutant. We conclude that EuNOD-CHI encodes a functional type-I CHI. In situ hybridization revealed that EuNOD-CHI expression is localized to the infected cells of the fixation zone in root nodules.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.413-413
• /
• 2005

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.3
• /
• pp.1847-1850
• /
• 2013

We conducted a hospital case-control study by genotyping four potential functional single nucleotide polymorphisms (SNPs) to assess the association of Xeroderma pigmentosum complementation group F (XPF) with gastric cancer susceptibility, and role of XPF polymorphisms in combination with H.pylori infection in risk definition. A total of 331 patients with gastric cancer and 355 controls were collected. Four SNPs of XPF, rs180067, rs1799801, rs2276466 and rs744154, were genotyped by Taqman real-time PCR method with a 7900 HT sequence detector system. The gastric cancer patients were more likely to have smoking habit, a family history of cancer and H.pylori infection. We did not find any significant difference in the genotype distributions of XPF rs180067, rs1799801, rs2276466 and rs744154 between cases and controls. However, multivariate logistic analysis showed a non-significant decreased risk in patients carrying rs180067 G allele, rs1799801 T allele or rs2276466 T allele genotypes. A non-significant increased risk of gastric cancer was found in individuals carrying the rs744154 GG genotype. Stratification by H.pylori infection and smoking was not significantly different in polymorphisms of XPF rs180067, rs1799801, rs2276466 and rs744154. The four XPF SNPs did not show significant interaction with H.pylori infection and smoking status (P for interaction was 0.35 and 0.18, respectively). Our study indicated that polymorphisms in rs180067, rs1799801, rs2276466 and rs744154 may affect the risk of gastric cancer but further large sample size studies are needed to validate any association.