A thermostable K+-stimulated vacuolar-type pyrophosphatase from the hyperthermophilic bacterium Thermotoga maritima
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Current evidence suggests the occurrence of two classes of vacuolar-type H+-translocating inorganic pyrophosphatases (V-PPases): K+-insensitive proteins, identified in eukaryotes, bacteria and archaea, and K+-stimulated V-PPases, identified to date only in eukaryotes. Here, we describe the functional characterization of a thermostable V-PPase from the anaerobic hyperthermophilic bacterium Thermotoga maritima by heterologous expression in Saccharomyces cerevisiae. The activity of this 71-kDa membrane-embedded polypeptide has a near obligate requirement for K+, like the plant V-PPase, and its thermostability depends on the binding of Mg2+. Phylogenetic analysis of protein sequences consistently assigned the T. maritima V-PPase to the K+-sensitive class of V-PPases so far only known for eukaryotes. The finding of a K+-stimulated V-PPase also in a member of a primitive eubacterial lineage strongly supports an ancient evolutionary origin of this group of pyrophosphate-energized proton pumps.
Originalsprog | Engelsk |
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Tidsskrift | FEBS Letters |
Vol/bind | 496 |
Udgave nummer | 1 |
Sider (fra-til) | 6-11 |
Antal sider | 6 |
ISSN | 0014-5793 |
DOI | |
Status | Udgivet - 4 maj 2001 |
ID: 272654340