Sodium/proton antiporter 1
| Na+/H+ antiporter 1 | |||||||||
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| Identifiers | |||||||||
| Symbol | Na_H_antiport_1 | ||||||||
| Pfam | PF06965 | ||||||||
| InterPro | IPR004670 | ||||||||
| TCDB | 2.A.36 | ||||||||
| OPM superfamily | 346 | ||||||||
| OPM protein | 1zcd | ||||||||
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Na+/H+ antiporter 1 family contains a number of bacterial sodium-proton antiporter (SPAP) 1 proteins. These are integral membrane proteins that catalyse the exchange of H+ for Na+ in a manner that is highly dependent on the pH.
In particular, the Escherichia coli NhaA Na+:H+ Antiporter (NhaA) protein probably functions in the regulation of the internal pH when the external pH is alkaline.[1] It also uses the H+ gradient to expel Na+ from the cell. Its activity is highly pH dependent.
A model[2] of the Last Universal Common Ancestor (LUCA) of all life on Earth suggests a SPAP was crucial for extracting energy from the natural proton gradients across the surface of underwater hydrothermal vents. A SPAP could have increased by 60% the free energy obtainable from proton gradients through a hypothesized leaky proto-membrane of LUCA; and a SPAP would have increasingly assisted proton pump efficiency in the less permeable membranes of LUCA's descendants, Archaea and Bacteria.
References
This article incorporates text from the public domain Pfam and InterPro IPR004670
- ↑ Karpel, R.; Alon, T.; Glaser, G.; Schuldiner, S.; Padan, E. (1991). "Expression of a sodium proton antiporter (NhaA) in Escherichia coli is induced by Na+ and Li+ ions". The Journal of Biological Chemistry 266 (32): 21753–21759. PMID 1657980.
- ↑ Sojo, Victor; Porniankowski, Andrew; Lane, Nick (August 12, 2014). "A Bioenergetic Basis for Membrane Divergence in Archaea and Bacteria". PLOS Biology 12 (8): e1001926. doi:10.1371/journal.pbio.1001926. Retrieved 18 August 2014.