Open AccessThe Putative Response Regulator BaeR Stimulates Multidrug Resistance of Escherichia coli via a Novel Multidrug Exporter System, MdtABC
Author(s) -
Satoshi Nagakubo,
Kunihiko Nishino,
Takahiro Hirata,
Akihito Yamaguchi
Publication year - 2002
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.184.15.4161-4167.2002
Subject(s) - biology , efflux , multiple drug resistance , novobiocin , multidrug resistance associated proteins , mutant , regulator , overproduction , escherichia coli , atp binding cassette transporter , microbiology and biotechnology , gene , drug resistance , genetics , transporter , antibiotics
Overproduction of the response regulator BaeR confers resistance to novobiocin and bile salts in a DeltaacrAB mutant by stimulating drug exporter gene expression. The mdtABC (multidrug transporter ABC, formerly known as yegMNO) genes, which encode a resistance-nodulation-cell division (RND) drug efflux system, are responsible for resistance. The MdtABC system comprises the transmembrane MdtB/MdtC heteromultimer and MdtA membrane fusion protein. MdtAC also confers bile salt, but not novobiocin, resistance. This indicates that the evolution from an MdtC homomultimer to an MdtBC heteromultimer contributed to extend the drug resistance spectrum. A BLAST search suggested that such a heteromultimer-type RND exporter constitutes a unique family among gram-negative organisms.