Glutamate 85 is involved in the sodium/proton exchange activity of the Escherichia coli ChaA.
Hitherto, the roles of specific amino acid residues of ChaA, one of three Na(+)/H(+) antiporters in Escherichia coli, in exchange activity have not been reported. Here we examined the role of acidic amino acid residues, Glu-85 and Glu-325, on the hydrophobic transmembrane domains. It was found that ChaA is involved in salt tolerance at alkaline pH. Mutagenesis analyses revealed the importance of Glu-85, but not Glu-325, in the exchange activity.
Fukaya
Fuminori
F
Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Japan.
Tanaka
Kimihiro
K
Waditee
Rungaroon
R
Tanaka
Yoshito
Y
Nakamura
Tatsunosuke
T
Takabe
Teruhiro
T
D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018698:Glutamic Acid; D009154:Mutation; D017434:Protein Structure, Tertiary; D011522:Protons; D012964:Sodium / Q000378:metabolism*
D029968:Escherichia coli Proteins; D011522:Protons; C470532:chaA protein, E coli; D018698:Glutamic Acid; D012964:Sodium