• 제목/요약/키워드: operon

검색결과 284건 처리시간 0.026초

Genetic Polymorphism among Korean Salmonids Determined by RAPD (Randomly Amplified Polymorphic DNA) Analysis

  • Park, Jung-Youn;Kim, Mi-Jung
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • 제12권2호
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    • pp.102-111
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    • 2007

  • RAPD analyses using 60 OPERON primers and 13 URPs were performed in order to assess the genetic variation and frequency of polymorphisms in Korean salmonids. RAPDS were very reproducible and most useful at the sub-species level. In RAPD analysis, 138 polymorphic bands were detected between Oncorhynchus masou subspecies and 99 bands were generated in two types of rainbow trout. Estimated genetic distances between O. masou subspecies were 0.28794, and between wild rainbow trout and an albino mutant was 0.22786. Each species of salmonid was well characterized using URP 4R, the obtained bands could be useful as a species specific RAPD markers.

  • https://doi.org/10.7850/jkso.2007.12.2.102 인용 PDF KSCI

Modulating the Properties of Metal-Sensing Whole-Cell Bioreporters by Interfering with Escherichia coli Metal Homeostasis

  • Yoon, Youngdae;Kang, Yerin;Lee, Woonwoo;Oh, Ki-Cheol;Jang, Geupil;Kim, Bong-Gyu
    • Journal of Microbiology and Biotechnology
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    • 제28권2호
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    • pp.323-329
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    • 2018

  • In Escherichia coli, the transcription of genes related to metal homeostasis is activated by the presence of target metals. The promoter regions of those genes can be fused with reporter genes to generate whole-cell bioreporters (WCBs); these organisms sense the presence of target metals through reporter gene expression. However, the limited number of available promoters for sensing domains restricts the number of WCB targets. In this study, we have demonstrated an alternative method to generate novel WCBs, based on the notion that since the sensing mechanisms of WCBs are related to metal transportation systems, their properties can be modulated by disrupting metal homeostasis. Mutant E. coli strains were generated by deleting the znt-operon genes zntA, which encodes a zinc-export protein, and zntR, which encodes a znt-operon regulatory protein, to investigate the effects on the metal-sensing properties of WCBs. Deletion of zntA increased the sensitivity but abolished the selectivity of cadmium-sensing WCBs, whereas arsenic-sensing WCBs gained sensitivity toward cadmium. When zntR was deleted, cadmium-sensing WCBs lost the ability to detect cadmium, and this was recovered by introducing exogenous zntR. In addition, the metal-binding site of ZntR was genetically engineered to modulate metal selectivity. This study provides a valuable platform for the development of novel E. coli-based WCBs.

  • https://doi.org/10.4014/jmb.1710.10012 인용 PDF KSCI

The Functions of the Riboflavin Genes in the lux Operon from Photobacterium Species (Photobacterium Species의 lux 오페론에서 발견된 Riboflavin 생합성 유전자들의 기능)

  • 이찬용;임종호
    • Korean Journal of Microbiology
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    • 제38권3호
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    • pp.173-179
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    • 2002

  • The functions of riboflavin synthesis genes ( ribI,II,III and IV) found immediately downstream of luxG in the lux operon from Photobacterium species were identified using the biochemical and genetical analysis. The ribI-III gene codes for protein corresponding to that coded by the second (riboflavin synthase), third (3,4-dihydroxy 2-butanone 4-phosphate synthase/GTP cyclohydrolase II) and fourth (lumazine synthase) gene, respectively, of Bacillus subtilis rib operon with the respective gene procuct sharing 41-50% amino acid sequence identity. Unexpectedly, the sequence of the ribIV product of Photobacterium phosphoreum does not correspond in sequence to the protein encoded by the fifth rib gene of Bacillus subtilis. Instead the gene (ribIV) codes for a polypeptide similar in sequence to GTP cyclohydrolase II of Escherichia coli and the carboxy terminal domain of the third rib gene from Bacillus subtilis. Complementation of Escherichia coli riboflavin auxotrophs showed that the function of the gene products of ribII and ribIV are DHBP synthase and GTP cyclohydrolase II, respectively. In addition the experiment, showing that increase in thermal stability of riboflavin synthase coded by ribIon coexpression with ribIII, provided indirect evidence that the latter gene codes for lumazine synthase.

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