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Enterococcus hirae vacuolar ATPase is expressed in response to pH as well as sodium
Author(s) -
Ikegami Miho,
Kawano Miyuki,
Takase Kazuma,
Yamato Ichiro,
Igarashi Kazuei,
Kakinuma Yoshimi
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00776-0
Subject(s) - enterococcus hirae , chloramphenicol acetyltransferase , mutant , acetyltransferase , atpase , operon , chemistry , microbiology and biotechnology , blot , biochemistry , chloramphenicol , biology , reporter gene , gene , enzyme , gene expression , enterococcus , acetylation , antibiotics
The Enterococcus hirae ntp operon encodes both a vacuolar ATPase, which transports Na + as well as Li + , and the KtrII K + transporter. A plasmid, in which the chloramphenicol acetyltransferase gene (CAT) was placed downstream of the ntp promoter, was introduced into a mutant totally defective in Na + extrusion. The CAT activity of this transformant was increased preferentially by addition of NaCl, but not by LiCl, in the media or by elevating the medium pH, correlating well with the increase in amounts of the ATPase subunits observed by Western blotting. The physiological significance of these responses of the ntp promoter is discussed.