Growth phase-dependent transcription of emrKY, a homolog of multidrug efflux emrAB genes of Escherichia coil, is induced by tetracycline

The Journal of General and Applied Microbiology

Katsuhide Yamasaki²  Ryutaro Utsumi²  Akinori Katoh²  Mayu Yamamoto²  Sachiko Yoshioka²  Hideaki Tagami¹  Motoki Furue²  Hiroji Aiba¹  Kanehisa Yamamoto²  Hiroyuki Tanabe² 

[1] Department of Molecular Biology, Faculty of Science, Nagoya University;Department of Agricultural Chemistry, Faculty of Agriculture, Kinki University

关键词: efflux pump;    Escherichia coli;    multidrug resistance;    tetracycline;   

DOI  :  10.2323/jgam.43.257

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

The genes emrK and emrY were found between genes dsdA and evgA at 51min on the Escherichia coli chromosome and form an operon. EmrK and EmrY are 50.4 and 63.3% identical in amino acid sequences to EmrA and EmrB, respectively, which together make up a multidrug resistant pump. To show that the emrKY operon can be expressed, we cloned the promoter with pMC1403 and constructed an emrK-lacZ' protein fusion plasmid, pMKD1. In E. coli MC4100 containing pMKD1, its expression was increased in the presence of a subinhibitory concentration of tetracycline, chloramphenicol or salicylate, but not by carbonylcyanide m-chlorophenylhydrazone, nalidixic acid or kanamycin. Furthermore, we have shown that emrKY transcription dependent on the growth phase is actually induced by tetracycline using a S1 nuclease protection assay.

【 授权许可】

Unknown