Affiliation:
1. Department of Microbiology, Faculty of Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, 700-8530, Japan
Abstract
ABSTRACT
NorM of
Vibrio parahaemolyticus
apparently is a new type of multidrug efflux protein, with no significant sequence similarity to any known transport proteins. Based on the following experimental results, we conclude that NorM is an Na
+
-driven Na
+
/drug antiporter. (i) Energy-dependent ethidium efflux from cells possessing NorM was observed in the presence of Na
+
but not of K
+
. (ii) An artificially imposed, inwardly directed Na
+
gradient elicited ethidium efflux from cells. (iii) The addition of ethidium to cells loaded with Na
+
elicited Na
+
efflux. Thus, NorM is an Na
+
/drug antiporting multidrug efflux pump, the first to be found in the biological world. Judging from the similarity of the NorM sequence to those of putative proteins in sequence databases, it seems that Na
+
/drug antiporters are present not only in
V. parahaemolyticus
but also in a wide range of other organisms.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
151 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献