Cloning and Expression of pcbCD Genes in Escherichia coli from Pseudomonas sp. DJ-12

Pseudomonas sp. DJ-12의 pcbCD 유전자의 클로닝과 Escherichia coli에서의 발현

  • Kim, Chi-Kyung (Department of Microbiology, Chungbuk National University) ;
  • Sung, Tae-Kyung (Department of Microbiology, Chungbuk National University) ;
  • Nam, Jung-Hyun (Department of Microbiology, Chungbuk National University) ;
  • Kim, Chang-Young (Department of Microbiology, Chungbuk National University) ;
  • Lee, Jae-Koo (Department of Agricultural Chemistry, Chungbuk National University)
  • Published : 1994.01.01

Abstract

The pcb genes of Pseudomonas sp. DJ-12 coded for the catabolism of polychlorinated biphenyl (PCBs) and biphenyl. The products of the pcbCD genes were 2,3-dihydroxy-4'-chlorobiphenyl dioxygenase and meta-cleavage product (MCP) hydrolase, which acted on degradation of 2,3-dihydroxy-4'-chlorobiphenyl to 4-chlorobenzoate. The pcbCD genes were cloned in E. coli XLl-Blue, and then the pcbD gene was further subcloned. As a metabolite transformed from 2,3-dihydroxybiphenyl by the cloned cell of E coli CU103, benzoate was detected by the resting cell assay. The enzyme activities of 2,3-dihydroxybiphenyl dioxygease and MCP hydrolase produced in the cloned cells E. coli CU103 and CU105 were about 17 and 3 times higher than those of Pseudomonas sp. DJ-12, respectively.

Polychlorinaed biphenyls(PCBs) 와 biphenyl을 분해하는 Pseudomonas sp. DJ-12에서는 그 초기 분해과정에 pcb ABCD 유전자들이 관여하고 있음이 밝혀졌다. 그 중 pcbCD와 pcdD 유전자를 E. coli XL1-Blue에 클로닝하여 E. coli CU103 과 CU105 균주를 각각 제조하였다. E. coli CU103은 2,3-dehydroxybuphenyl dioxygenase(2,3-DHBP)와 meta-cleavage compound(MCP) hydrolase를 생성하여 2,3-dihydroxybiphenyl을 benzoate로 변환시켜 주었다. E. coli CU1 과 CU103 에서 pcbC 유전자의 산물인 2,3-DHBP dioxygense의 활성도는 Pseudomonas sp. DJ-12에서 보다 약 17배 높았으며, E. coli CU105에서 pcbD의 산물인 MCP hydrolase는 약 3배 더 높게 나타났다.

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