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
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Research Support, Non-U.S. Gov't
MeSH terms
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Bacterial Proteins / chemistry*
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism*
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Catalysis
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Enterococcus / chemistry
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Enterococcus / enzymology*
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Enterococcus / genetics
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Enterococcus / physiology
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Glutamates / chemistry
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Glutamates / genetics
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Glutamates / metabolism
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Lithium / metabolism
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Protein Subunits / chemistry
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Protein Subunits / genetics
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Protein Subunits / metabolism
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Salt Tolerance*
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Sodium / metabolism
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Vacuolar Proton-Translocating ATPases / chemistry*
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Vacuolar Proton-Translocating ATPases / genetics
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Vacuolar Proton-Translocating ATPases / metabolism*
Substances
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Bacterial Proteins
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Glutamates
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Protein Subunits
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Lithium
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Sodium
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Vacuolar Proton-Translocating ATPases