Kinetic properties of NhaB, a Na+/H+ antiporter from Escherichia coli
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چکیده
منابع مشابه
Kinetic properties of NhaB, a Na+/H+ antiporter from Escherichia coli.
NhaB, a Na+/H+ antiporter from Escherichia coli, was overproduced, purified, and reconstituted in a functional state, demonstrating that a single polypeptide, the product of the nhaB gene, can catalyze full activity. NhaB is a minor protein that accounts for less than 0.1% of the total membrane protein. The use of proteoliposomes made possible the determination of important kinetic and pharmaco...
متن کاملPhysiological role of nhaB, a specific Na+/H+ antiporter in Escherichia coli.
The nhaB gene which codes for Na+/H+ antiporter activity in Escherichia coli was recently cloned (Pinner, E., Padan, E., and Schuldiner, S. (1992) J. Biol. Chem. 267, 11064-11068). In order to elucidate the role of nhaB in Na+ and H+ ions physiology and its interaction with nhaA, we generated mutants in which the chromosomal gene has been inactivated by insertion/deletion. A mutant devoid of bo...
متن کاملCloning, sequencing, and expression of the nhaB gene, encoding a Na+/H+ antiporter in Escherichia coli.
In Escherichia coli, expulsion of sodium ions is driven by proton flux via at least two distinct Na+/H+ antiporters, NhaA and NhaB. When the nhaA gene is deleted from the chromosome, the cell becomes sensitive to high salinity and alkaline pH (Padan, E., Maisler, N., Taglicht, D., Karpel, R., and Schuldiner, S. (1989) J. Biol. Chem. 264, 20297-20302). In the current work we cloned the nhaB gene...
متن کاملFunctional expression of the Enterococcus hirae NaH-antiporter in Escherichia coli.
We recently described the cloning of napA, the putative structural gene for the NaH-antiporter of Enterococcus hirae (Waser, M., Bienz-Hess, D., Davies, K., and Solioz, M. (1992) J. Biol. Chem. 267, 5396-5400). To analyze the gene product of napA, we expressed it in Escherichia coli. When placed under the control of a T7 promoter, napA could be transcribed and labeled specifically with [35S]met...
متن کاملANTIPORTER NhaA FROM ESCHERICHIA COLI. AN ELECTROPHYSIOLOGICAL STUDY*
gradient for activation, both the wt and the pH-shifted G338S variant exhibit highly symmetrical transport activity with bell shaped pH dependencies, but the optimal pH was shifted 1.8 pH units to the acidic range in the variant. In both strains the pH dependence was associated with a systematic increase of the Km for Na + at acidic pH. Under symmetrical Na + concentration with a pH gradient fo...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1994
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)47190-6