Cloning and Overexpression of the Mitomycin C Resistance Gene (mcr) from Streptoverticillium caespitosum.
Streptoverticillium caespitosum ATCC27422 is a major producer of an anti-cancer drug, mitomycin C. A 6.6 kb DNA fragment containing the mitomycin C resistance gene (mcr) was isolated from ATCC27422 by shotgun method in order to learn the molecular mechanism of mitomycin C resistance. By constructing a series of subclones from this 6.6 kb DNA fragment, the mitomycin C resistance gene was localized on a 3.1 kb DNA fragment. Sequence analysis revealed that the open reading frame of mcr gene was 1 347 bp in size, encoding 448 amino acids with ATG as initiation codon and TGA as termination codon. The mcr gene was specifically expressed under the control of T7 promoter in E.coli, and the resistance to mitomycin C in the transformant was over 100-fold higher than that in wild-type strain. The overexpression of mcr gene in E.coli is very helpful for the further research about the molecular mechanism of drug resistance.
Huang
Jian-Qiang
JQ
Shanghai Institute of Plant Physiology, the Chinese Academy of Sciences, Shanghai 200032, China. ylyang@iris.sipp.ac.cn
Lu
Yong-Tao
YT
Jiang
Wei-Hong
WH
Zhang
Jing
J
Zhao
Guo-Ping
GP
Yang
Yun-Liu
YL