• 생명과학회지
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• 제2권1호
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• pp.2-10
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• 1992

cAMP-CRP complex에 의해 전사조절을 받는 관련유전자의 구조, 특징, 조절양상, 기작과 CRP의 생화학적 및 분자생물학적이해 등을 살폈다. 그러나 대장균의 전체유전자의 구조해석이 연구사업으로 실행되어지고 있는 현실에서 볼 때 CRP의 조절하에 있는 유전자군이 보다 더 복잡 다양한 system으로 생각되어져서 CRP조절계의 전체적인 양상으로 해명하기 위한 연구도 이루어질 것으로 생각되어진다. 즉, cAMP-CRP의 조절하에 있는 조절영역의 전체를 파악함은 operon의 발현조절의 해명에 중요한 기틀이 될 뿐만 아니라 개별유전자의 이해를 위한 것보다 복잡한 세포 전체의 제어계를 분자적수준에서 해결하는데 중요한 과제라고 사료되어진다. 몇 가지 연구 결과에서는 cAMP-CRP가 결합은 하면서도 발현조절에는 관여하지 않는다든지, cAMP가 결합하지 않으면서도 전사조절을 받을 수 있는 유전자들이 밝혀지고 있다.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.245-249
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• 1995

Expression of the adjacent but divergently transcribed glpD and glpE gene is positively regulated by cAMP-CRP. In this study, we constructed several mutants in which a CRP-binding site is placed at different distances upstream of the glpD promoter. The effect of the spacer length on transcription activation by cAMP-CRP was tested in vivo by $\beta$-galactosidase. The cAMP-CRP complex activated transcription from glpD when bound at a number of positions, all of which lay on the same face of the DNA helix, although the degree of activation varied with the length of the spacer. By contrast, the insertion of spacer length with non-integral turns of the DNA helix extremely inhibited the activation of transcription. The observed transcription activation by cAMP of the glpD promoter was influenced by the distance between the CRP binding site and the transcription start point.

• 생명과학회지
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• 제13권5호
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• pp.746-750
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• 2003

Lactose operon contains two CRP binding sites at promoter(CRP1 site) and operator(CRP2 site) regions at lac operon. CRP protein can bind to both sites with the different binding affinity. CRP1 site, major CRP binding site, acts the transcription activation with the fully unknown mechanism by binding of CRP. In this study, the binding affinities of CRP1 site and CRP2 site were measured with the fluorescein-labeled oligomers, which contain CRP1 site and the three different spacing sequences between GTGA and TCAC at CRP2 site. Results showed that CRP:cAMP complex bound to CRP1 site 3 times more strongly than CRP2 site and the base spacing between GTGA and TCAC was not the only factor to affect the binding affinity of CRP to CRP2 site.

• 생명과학회지
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• 제5권4호
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• pp.162-169
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• 1995

The glpD genes encoding gly-3-p dehydrogenase is essential for the aerobic growth of E. coli on glycerol or gly-3-p. The glpE gene, the function of which is unknownm is transcribed divergently with respect to glpD gene. Expression of the adjacent but divergently transcribed glpD the glpE genes is positively regulated by the cAMP-CRP complex. In this study, for a precise investigation of the functional elements in the regulatory region for transcription activation by cAMP-CRP, deletion mutation have been introducted into the regulatory region. The effect of the deletion mutant on transcriptional regulation was tested in vivo by $\beta$-galctosidase activity. Deletion mutants in the regulatory region of glpD demonstrated that the presence of the CRP-binding site resulted in an sixfold increase in promoter activity. And also deletion mutants of glpE gene demonstrated that the presence of the CRP-binding site resulted in an eightfold increase in promoter activity. Insertion of 22 bp oligomer in the deletion mutants has shown that the CRP binding site is need for maximal expression of glpD and glpE genes. glpD and glpE gene, cAMP-CRP complex, deletion mutant, transcriptional regulation.

• 한국자기공명학회논문지
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• 제1권1호
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• pp.31-44
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• 1997

The effect of the binding of CRP to the symmetrically synthetic 22, 28, and 30 bp lac promoter was investigated by 1H NMR. The binding of cAMP*CRP to the 22 bp DNA did not bring about any changes in the chemical shift values, but did cause selective line broadening of imino proton resonances of specific base pairs. However, The binding of cAMP*CRP to the 28 and 30 bp DNA brought about large changes on the imino proton resonances that seems to be induced by DNA bending. We studied also the role of cAMP as an activator of DNA/CRP complex formation by gel mobility shift assay. Gel mobility shift assay revealed that the cAMP*CRP complex was not able to bind to the 22 bp DNA fragment, but was able to bind to the 28 bp DNA fragment of lac promoter region.

• Molecules and Cells
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• 제26권1호
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• pp.61-66
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• 2008

Cyclic AMP receptor protein (CRP) is allosterically activated by cAMP and functions as a global transcription regulator in enteric bacteria. Structural information on CRP in the absence of cAMP (apo-CRP) is essential to fully understand its allosteric behavior. In this study we demonstrated interdomain interactions in apo-CRP, using a comparative thermodynamic approach to the intact protein and its isolated domains, which were prepared either by limited proteolysis or using recombinant DNA. Thermal denaturation of the intact apo-CRP, monitored by differential scanning calorimetry, revealed an apparently single cooperative transition with a slight asymmetry. Combined with circular dichroism and fluorescence analysis, the thermal denaturation of apo-CRP could be interpreted as a coupled process involving two individual transitions, each attributable to a structural domain. When isolated individually, both of the domains exhibited significantly altered thermal behavior, thus pointing to the existence of non-covalent interdomain interactions in the intact apo-CRP. These observations suggest that the allosteric conformational change of CRP upon binding to cAMP is achieved by perturbing or modifying pre-existing interdomain interactions. They also underline the effectiveness of a comparative approach using calorimetric and structural probes for studying the thermodynamics of a protein.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1996년도 정기총회 및 학술발표회
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• pp.19-19
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• 1996

Cyclic AMP receptor protein (CRP) from E. Coli plays a key role in regulation of the expression of more than 20 genes of the bacterium. CRP binds in the presence of cAMP to a specific target site near the promoter of each gene under its regulation. CRP is a dimer (Mr～47,000) of two identical subunits. There are two binding domains in the CRP monomer, one for the binding of the cAMP and the other for the binding of specific DNA sequences. (omitted)

• Journal of Microbiology
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• 제45권3호
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• pp.234-240
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• 2007

The DcuS-R two-component system of Escherichia coli senses $C_{4}-dicarboxylates$ of the medium and regulates expression of the genes related to utilization of them. It is known that phospho-DcuR induces expression of genes such as the dcuB-fumB operon, the frdABCD operon, and the dctA gene. We analyzed promoters of the dcuS-R operon to elucidate the transcriptional regulation system. We found a novel internal promoter within the dcuS gene that is regulated by the transcriptional regulator, CRP-cAMP, in both aerobic and anaerobic conditions.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1392-1396
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• 2005

Proteolytic digestion and CD measurement of wild-type and mutant cyclic AMP receptor proteins (CRPs) were performed either in the presence or absence of cyclic nucleotide. Results indicated that transition of a structural change to the hinge region by the binding of cAMP to the anti site was required for the binding of cAMP to the syn site near the hinge region and, although the occupancy of cAMP in the anti site increased the protein stability, CRP adopted more a stable conformation by the binding of cAMP to the syn site.

• BMB Reports
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• 제30권5호
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• pp.320-325
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• 1997

Thioredoxin is a multi-functional protein which is ubiquitous in microorganisms, animals and plants. Previously, expression of the E. coli thioredoxin gene was found to be negatively regulated by cAMP. In the present study, the effect of cAMP on two separate promoters of the E. coli thioredoxin gene was investigated. Cyclic AMP had a repressible effect on P1 and P1P2 promoter activity of the constructs. This effect was also observed in the cya strain. The P2 promoter construct gave very high -galactosidase activity, and its expression was not affected by exogenous cAMP. It was assumed that a cis-acting negative element, probably the cAMP-CRP binding site, might have been deleted in the P1 promoter construct. Repression of the thioredoxin gene expression by cAMP appeared to be independent of ppGpp.