Significance of the glutamate-139 residue of the V-type Na+-ATPase NtpK subunit in catalytic turnover linked with salt tolerance of Enterococcus hirae

Miyuki Kawano-Kawada; Hiroko Takahashi; Kazuei Igarashi; Takeshi Murata; Ichiro Yamato; Michio Homma; Yoshimi Kakinuma

doi:10.1128/JB.01537-10

Significance of the glutamate-139 residue of the V-type Na+-ATPase NtpK subunit in catalytic turnover linked with salt tolerance of Enterococcus hirae

J Bacteriol. 2011 Jul;193(14):3657-61. doi: 10.1128/JB.01537-10. Epub 2011 May 20.

Authors

Miyuki Kawano-Kawada¹, Hiroko Takahashi, Kazuei Igarashi, Takeshi Murata, Ichiro Yamato, Michio Homma, Yoshimi Kakinuma

Affiliation

¹ Integrated Center for Sciences, Ehime University, Matsuyama, Japan1; Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan.

Abstract

A Glu139Asp mutant of the NtpK subunit (kE139D) of Enterococcus hirae vacuolar-type ATPase (V-ATPase) lost tolerance to sodium but not to lithium at pH 10. Purified kE139D V-ATPase retained relatively high specific activity and affinity for the lithium ion compared to the sodium ion. The kE139 residue of V-ATPase is indispensable for its enzymatic activity that is linked with the salt tolerance of enterococci.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacterial Proteins / chemistry*
Bacterial Proteins / genetics
Bacterial Proteins / metabolism*
Catalysis
Enterococcus / chemistry
Enterococcus / enzymology*
Enterococcus / genetics
Enterococcus / physiology
Glutamates / chemistry
Glutamates / genetics
Glutamates / metabolism
Lithium / metabolism
Protein Subunits / chemistry
Protein Subunits / genetics
Protein Subunits / metabolism
Salt Tolerance*
Sodium / metabolism
Vacuolar Proton-Translocating ATPases / chemistry*
Vacuolar Proton-Translocating ATPases / genetics
Vacuolar Proton-Translocating ATPases / metabolism*

Substances

Bacterial Proteins
Glutamates
Protein Subunits
Lithium
Sodium
Vacuolar Proton-Translocating ATPases