[Coexpression of caiB and caiE with two plasmids in E. coli].
Recombinant bacteria exhibiting high enzymatic activities were obtained by cloning and coexpression of both caiB gene and caiE gene in the host of E. coli Bl21(DE3), which encode carnitine dehydratase and a protein related to the synthesis of cofactor for carnitine dehydratase, respectively. In order to coexpress these two genes, compatible and incompatible two plasmids system were used, the difference between them was also studied. After induction with IPTG, both caiB and caiE genes were coexpressed in both compatible two plasmids system and incompatible two plasmids system. In the former system, the expressed products accounted for 17% and 10% of the total proteins in the host; in the later system, the proportion was 39% and 20%, respectively. The activity of carnitine dehydratase in E. coli Bl21(DE3) with either coexpression system is about 2.3 times than that in E. coli Bl21(DE3) with only pET28-caiB. The plasmids stabilities in these two systems were the same, all needed the help of antibiotic selective pressure.
Fan
Li-Qiang
LQ
Institute of Biochemistry, East China University of Science and Technology, Shanghai 200237, China.
Yuan
Qin-Sheng
QS
Wu
Xiang-Fu
XF
D000217:Acyltransferases / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D010957:Plasmids / Q000235:genetics
D001426:Bacterial Proteins; D000217:Acyltransferases; C060278:crotonobetainyl-CoA carnitine coenzyme A transferase