• 한국광과학회:학술대회논문집
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• 한국광과학회 2000년도 학술대회지
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• pp.18-18
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• 2000

• 한국식물학회:학술대회논문집
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• 한국식물학회 2000년도 춘계학술발표대회:발표눈문요지록
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• pp.24-24
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• 2000

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.114-120
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• 2002

A 1,989-bp genomic region encoding nickel resistance genes was isolated from Legionella pneumophila, a pathogen for legionellosis. From a sequencing and computer analysis, the region was found to harbor two structural genes, a nreB-like protein gene (1,149 bp) and a nreA-like protein gene (270 bp), in a row. Both genes exhibited a significant degree of similarity to the corresponding genes from Synechocystis sp. PCC6803 ($54\%$ amino acid sequence identity) and Achromobacter xylosoxidans 31A ($76\%$). The gene was successfully expressed in E. coli MG1655 and conferred a nickel resistance of up to 5 mM in an LB medium and 3 mM in a TMS medium including gluconate as the sole carbon source. E. coli harboring the nickel resistance gene also exhibited a substantial resistance to cobalt, yet no resistance to cadmium or zinc. Since the extracellular concentration of nickel remained constant during the whole period of cultivation, it was confirmed that the nickel resistance was provided by an efflux system like the $Ni^2＋$permease (nrsD) of Synechocystis sp. strain PCC6803. Since polyphosphate (poly-P) is known as a global regulator for gene expression as well as a potential virulence factor in E. coli, the nickel resistance of a ppk mutant of E. coli MG 1655 harboring the nickel resistance gene from L. pneumophila was compared with that of its parental strain. The nickel resistance was significantly attenuated by ppk inactivation, which was more pronounced in an LB medium than in a TMS medium.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.126-126
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• 2003

Sucrose-phosphate synthase (SPS) is a key regulatory enzyme in sucrose synthesis. To investigate the role of SPS in carbon partitioning, we produced transgenic rice plants overexpressing a cyanobacterial SPS from Synechocystis sp. PCC 6803. The gene was expressed under the control of the maize Ubil promoter in transgenic plants. Southern and Northern blot analyses confirmed the integration and the expression of the transgene in four transgenic rice lines. All of the four transgenic! lines analyzed showed abnormal vegetative and reproductive developments. Analysis of SPS activities and primary metabolites in the transgenic rice plants will be presented.

• Bulletin of the Korean Chemical Society
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• 제18권8호
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• pp.874-880
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• 1997

Various classes of phospholipids were investigated for the structural determination of fatty acyl groups by fast atom bombardment tandem mass spectrometry (FAB-MS/MS). Phospholipids were desorbed by FAB as molecules chelated with sodium ion (or ions). Collision-induced dissociation (CID) of intact sodium adduct molecular ions ([M+Na]+, [M-H+2Na]+ or [M+Na-2H]-) produced a series of homologous fragment ions via the charge-remote fragmentation along the fatty acid chains. These ions were found useful to locate the double bond positions even for the polyunsaturated fatty acid chains. The regiospecificity of the acyl chain linkages in phosphatidylcholine (PC) could also be determined based on the ratio of relative abundance of the product ions (i.e., [M+Na-85-R2COOH]+ vs [M+Na-85-R1COOH]+) in CID-MS/MS of [M+Na]+. These are generated by the loss of fatty acyl groups at sn-1 and sn-2, respectively, together with the choline group. In all the phospholipid compounds investigated, loss of the fatty acid at the sn-2 position was dominant. The present method was applied to the structural determination of molecular species of phosphatidylglycerols (PG) isolated from cyanobacterium Synechocystis sp. PCC 6803.