• Plant Biotechnology Reports
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• 제4권3호
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• pp.193-199
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• 2010

An olive-green mutant was generated in Synechocystis sp. strain PCC 6803 by inactivation of the sll0396 gene. Whole-cell absorption spectra of the mutant revealed the missing of phycocyanin peak. An investigation of the low-temperature fluorescence emission spectra revealed that the $sll0396{\Omega}$ mutant has a reduced amount of phycocyanin. Western blot analysis showed that the mutant contained less phycocyanin ${\beta}$- and ${\alpha}$-subunits and lacked the 30- and 32-kDa linker polypeptides, and northern blot analysis revealed that the transcription of the 1.4-kb cpcBA gene encoding the phycocyanin ${\beta}$- and ${\alpha}$-subunits was lower in the mutant. The Sll0396 protein has a DNA-binding motif and shares homology with known response regulators. Our results indicate that Sll0396 plays a regulatory role in the transcription of the phycocyanin genes during phycobilisome synthesis.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.447-454
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• 2009

The transport of spermidine into a cyanobacterium, Synechocystis sp. pec 6803, was characterized by measuring the uptake of $^{14}C$-spermidine. Spermidine transport was shown to be saturable with an apparent affinity constant ($K_m$) value of $67{\mu}M$ and a maximal velocity ($V_{max}$) value of 0.45 nmol/min/mg protein. Spermidine uptake was pH-dependent with the pH optimum being 8.0. The competition experiment showed strong inhibition of spermidine uptake by putrescine and spermine, whereas amino acids were hardly inhibitory. The inhibition kinetics of spermidine transport by putrescine and spermine was found to be noncompetitive with $K_i$ values of 292 and $432{\mu}M$, respectively. The inhibition of spermidine transport by various metabolic inhibitors and ionophores suggests that spermidine uptake is energy-dependent. The diminution of cell growth was observed in cells grown at a high concentration of NaCl. Addition of a low concentration of spermidine at 0.5 mM relieved growth inhibition by salt stress. Upshift of the external osmolality generated by either NaCl or sorbitol caused an increased spermidine transport with about 30-40% increase at 10 mosmol/kg upshift.

• 아시안잔디학회지
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• 제11권1호
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• pp.59-72
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• 1997

The influence of respiration on photosythetic electron transport were investigated in the Wid type and psaB mutants from Syneehocystis sp. PCC6803. The amount of glucose uptake in the wild type was proportional to the glucose concentration added in wild type and less than that of psaB mutants in the dark. It was suggested that psaB mutants more depend on the glucose than the wild type. It was investigated how the activities of isocitrate dehydrogenase(IDH) and glucose-6-phos-phate dehydrogenase(G6PDH) were changed. The activities of IDH were very low. While, the ac-tivities of G6PDH were much higher than that of IDH. These results agree to the reports that ex-ogenous glucose was dismilated aerobically via Oxidative Pentose Phosphate Pathway in heterotrophic cyanobacteria. PsaB mutants showed high G6PDH activity in the presence of glucose as well as in the dark and high respiratory activities especially in the dark. It was also investigated how photosynthetic electron transport activities were changed. PsaB mutants showed higher photosynthetic electron tranasport activities than wild type in the presence of glucose as well as in the dark. In the results, it was proposed that photosynthetic electron transport between PS I and PS U was complemented by respiratory electron transport through the NADPH generated by Dxidative Pentose Phophate Pathway in psaB mutant from Synechocystis sp. PCC6803. Key words: Photosynthetic electron transport, Respiration, Synechoystis sp. PCC6803, psaB mutant, Glucose uptake, IDH, G6PDH, Respiratory electron transport activity.

• 미생물학회지
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• 제36권4호
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• pp.249-253
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• 2000

Cyanobacteria의 광합성 보조색소인 phycocyanin의 PC operon(cpc gene)을 PCR로 증폭하고, 제한효소로 처리하여 RFLP pattern을 비교하였다. Intergenic spacer sequence를 포함한 cpc gene은 실험에 사용한 cyanobacteria 균주 모두에게 증폭되었으며, 산물의 size는 약 700 bp였다. PCR산물을 5종의 제한효소로 처리한 결과 AluI, MspI, HaeIII는 같은 속내으ㅐ 균주간에 동일한 pattern을 나타내어 속 구분이 가능하였으며 CfoI은 Anabeana와 Synechocystis속의 균주간에 구별되는 양상을 나타내어 속내 균주 구별에 유용하였다. Restriction enzyme profile에 의한 phenogram에서 Anabeana, Chlorogloea, Synechyhocystis는 각각 하나의 cluster를 형성하여 cyanobacteria의 분류에 PC-IGS의 RFLP pattern이 유용함을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.166-169
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• 2012

In several biotechnological applications of living bacterial cells with inducible gene expression systems, the extent of overexpression and the specificity to the inducer are key elements. In the present study, we established the concentration ranges of $Zn^{2+}$, $Ni^{2+}$, $Co^{2+}$, ${AsO_2}^-$, and $Cd^{2+}$ ions that caused significant activation of the respective promoters of Synechocystis sp. without concomitant unspecific stress responses. The low expression levels can be increased up to 10-100-fold upon treatments with $Cd^{2+}$, ${AsO_2}^-$, $Zn^{2+}$, and $Co^{2+}$ ions and up to 800-fold upon $Ni^{2+}$ treatment. These results facilitate the development of conditional gene expression systems in cyanobacteria.

• 한국식품영양학회지
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• 제23권4호
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• pp.526-530
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• 2010

Synechocystis sp. PCC6803의 type II Isopentenyl diphosphate isomerase gene(sll1556, Syidi2)의 특성을 살펴보기 위하여 ${\Delta}idi$인 E. coli $DH5{\alpha}$를 제작하고, 이 균주에서 cloning하고 발현시켰다. 라이코펜 합성 유전자들(crtE, crtB, and crtI)과 mevalonate pathway 유전자들(MvK1, MvK2, Mvd)를 함유한 ${\Delta}idi$ E. coli $DH5{\alpha}$ 균주를 mevalonate가 함유된 LB 배지에서 배양하면 mevalonate pathway 유전자들을 함유한 E. coli $DH5{\alpha}$균주는 mevalonate에 의해 생성된 isopentenyl diphosphate의 독성에 의해 매우 느린 성장을 보였다. 라이코펜 합성유전자들과 mevalonate 합성유전자들을 함유한 ${\Delta}idi$ E. coli $DH5{\alpha}$ 균주에 Syidi2를 도입한 결과, mevalonate가 함유된 LB배지에서 균체의 성장이 완전히 회복되었으며, 라이코펜이 합성되었음을 나타내는 붉은 균락이 형성되었다. 이에 따라, SyIdi1과 ECidi를 도입하여 비교한 결과, 라이코펜 합성 유전자들과 mevalonate pathway 유전자들을 함유한 ${\Delta}idi$ E. coli $DH5{\alpha}$ 균주 자체와 SyIdi1을 도입한 라이코펜 합성 유전자들과 mevalonate pathway 유전자들을 함유한 ${\Delta}idi$ E. coli $DH5{\alpha}$ 균주는 IPP의 독성에 의해 성장이 매우 느렸으나, SyIdi2, RSidi, HPidi, 및 ECidi를 함유하고 있는 ${\Delta}idi$ E. coli $DH5{\alpha}$ 균주는 균체의 성장과 라이코펜의 합성을 완전히 회복하였으며, 그중 가장 우수한 라이코펜 생합성 결과를 나타낸 것은 pSUP-LYCSyIdi2로서 균체당 라이코펜 생성량이 control 대비 2.8배이었다.

• 미생물학회지
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• 제41권1호
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• pp.67-73
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• 2005

본 연구에서는 남세균인 Synechocystis sp. PCC 6803 (Syn6803)을 대상으로 transposable element Tn5를 이용하여 획득된 1,200여 돌연변이주로부터 모균주에 비하여 PHB 축적량이 크게 증진된 균주를 선별하고, Tn5 삽입에 의해 결함을 나타낸 유전자를 확인함으로써 Syn6803에서의 PHB 생합성에 영향을 주는 세포내 생리학적 요인을 조사하고자 하였다. 모균주인 야생형 균주의 경우 질소원이 제한된 $BG11_0$ 배지에서의 PHB 생합성량이 건체량의 $4\%$ (w/w) 수준인데 반하여, $10-34\%$의 생합성량을 보이는 25개의 돌연변이 균주를 얻을 수 있었다. Inverse PCR을 이용하여, 선별된 돌연변이 균주내 돌연변이가 일어난 유전자를 조사한 결과, 아직까지 그 기능이 규명되지 않은 유전자가 대부분이었으나, NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase 또는 photosystem II PsbT protein과 같이 광합성과 호흡에 관여하는 유전자에 돌연변이가 일어난 4 균주와 histidine kinase가 결여된 1균주가 확인되었다. 이들 균주를 대상으로pulse-amplitude modulated fluorometer를 이용하여 세포내 $NAD(P)H/NAD(P)^+$비를 측정한 결과, 에너지 대사 흐름의 차단에 의해 세포내의 $NAD(P)HNAD(P)^+$비가 모균주에 비하여 현저하게 높은 것으로 나타났다. 이는 잉여의 전자로 포화된 세포, 즉 NAD(P)H에 의해 환원적 상태를 유지하고 있는 세포의 경우 PHB 축적 이 증진될 수 있음을 시사한다. 이러한 사실은 인위적으로 광합성과 호흡 관련 유전자가 제거되어 $NAD(P)H/NAD(P)^+$비가 높아진 것으로 알려진 다수의 Syn6803 돌연변이 균주들을 대상으로 PHB 생합성량을 조사한 결과로부터 재확인되었다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.304.2-304
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• 1998

• 한국유전체학회:학술대회논문집
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• 한국유전체학회 2003년도 The 12th Korea Genome Conference
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• pp.40.1-40.1
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• 2003

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.203-205
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• 2002

Light is an environmental signal that regulates photomovement and main energy source of photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803 (Syn6803). Syn6803 is a popular model system for study of plant functional genomics. In this report, we adopted 2D gel based proteomics study to investigate proteins related with the light absorption and photo-protection in Syn6803. More than 700 proteins were detected on the SDS-gels stained with silver nitrate. Several proteins showing different expression level under various light conditions were identified with MALDI-TOF Mass spectrometry. As a comparison, we also conducted ICAT-based proteome study using WT and cphl (cyanobacterial phytochrome 1) mutant. A cphl deletion led to changes in the expression of proteins involved in translation, photosynthesis including photosystem and CO2 fixation, and cellular regulation. We are currently involved in TAP-tagging method to study protein-protein interactions in search for the molecular component involved in the light signal transduction of Syn6803 photomovement.