Residue aspartate-147 from the third transmembrane region of Na(+)/H(+) antiporter NhaB of Vibrio alginolyticus plays a role in its activity.
نویسندگان
چکیده
NhaB is a bacterial Na(+)/H(+) antiporter with unique topology. The pH dependence of NhaB from Vibrio alginolyticus differs from that of the Escherichia coli NhaB homolog. Replacement of Asp-147 with Glu made high H(+) concentrations a requirement for the NhaB activity. Replacement of Asp-147 with neutral amino acids inactivated NhaB.
منابع مشابه
Cloning, 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...
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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...
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ورودعنوان ژورنال:
- Journal of bacteriology
دوره 183 19 شماره
صفحات -
تاریخ انتشار 2001