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

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.

SUBMITTER: Kawano-Kawada M

PROVIDER: S-EPMC3133306 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

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

Kawano-Kawada Miyuki M Takahashi Hiroko H Igarashi Kazuei K Murata Takeshi T Yamato Ichiro I Homma Michio M Kakinuma Yoshimi Y

Journal of bacteriology 20110520 14

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. ...[more]

PMID: 21602356

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