ArticleProceedings of the National Academy of Sciences of the United States of America2011
The pivotal twin histidines and aromatic triad of the Escherichia coli ammonium channel AmtB can be replaced.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers.
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Who cites it
16 citing papers in PubMed, 24 citations in OpenAlex.
- Biological ammonium transporters from the Amt/Mep/Rh superfamily: mechanism, energetics, and technical limitations.Bioscience reports · 2024Review
- Local Attraction of Substrates and Co-Substrates Enhances Weak Acid and Base Transmembrane Transport.Biomolecules · 2022Review
- Article
- A twin histidine motif is the core structure for high-affinity substrate selection in plant ammonium transporters.The Journal of biological chemistry · 2020Article
- A pore-occluding phenylalanine gate prevents ion slippage through plant ammonium transporters.Scientific reports · 2019Article
- The lipid environment determines the activity of the Escherichia coli ammonium transporter AmtB.FASEB journal : official publication of the Federation of American Societies for Experimental Biology · 2019Article
- The ctenidium of the giant clam, Tridacna squamosa, expresses an ammonium transporter 1 that displays light-suppressed gene and protein expression and may be involved in ammonia excretion.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2018Article
- Molecular characterization of two Rhesus glycoproteins from the euryhaline freshwater white-rimmed stingray, Himantura signifer, and changes in their transcript levels and protein abundance in the gills, kidney, and liver during brackish water acclimation.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2017Article
- Article
- Direct observation of electrogenic NH4(+) transport in ammonium transport (Amt) proteins.Proceedings of the National Academy of Sciences of the United States of America · 2014Article
- Switching substrate specificity of AMT/MEP/ Rh proteins.Channels (Austin, Tex.) · 2014Review
- Nitrogen assimilation in Escherichia coli: putting molecular data into a systems perspective.Microbiology and molecular biology reviews : MMBR · 2013Review
- A molecular pathway for the egress of ammonia produced by nitrogenase.Scientific reports · 2013Article
- The molecular basis of K+ exclusion by the Escherichia coli ammonium channel AmtB.The Journal of biological chemistry · 2013Article
- Article
- High affinity ammonium transporters: molecular mechanism of action.Frontiers in plant science · 2012Article
Corrections and comments
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Authors and funding
2 authors at 1 institution in 1 country.
Funding
Abstract
In Escherichia coli, each subunit of the trimeric channel protein AmtB carries a hydrophobic pore for transport of NH(4)(+) across the cytoplasmic membrane. Positioned along this substrate conduction pathway are two conserved elements--a pair of hydrogen-bonded histidines (H168/H318) located within the pore itself and a set of aromatic residues (F107/W148/F215) at its periplasmic entrance--thought to be critical to AmtB function. Using site-directed mutagenesis and suppressor genetics, we examined the requirement for these elements in NH(4)(+) transport. This analysis shows that AmtB can accommodate, by either direct substitution or suppressor generation, acidic residues at one or both positions of the H168/H318 twin-histidine site while retaining near wild-type activity. Similarly, study of the F107/W148/F215 triad indicates that good-to-excellent AmtB function is preserved upon individual and simultaneous replacement of these aromatic amino acids with aliphatic residues. Our findings lead us to conclude that these elements and their component parts are not required for AmtB function, but instead serve to optimize its performance.
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Registered trials
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