Difference between revisions of "Part:BBa K1675001"
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The gene, ''NhaB'', is the archetypal sodium/proton anti-porter in ''E. coli''. It is crucial when ''NhaA''’s activity is limited, such as ''NhaA'' is not sufficiently induced, or ''NhaA'' is not activated.
 
The gene, ''NhaB'', is the archetypal sodium/proton anti-porter in ''E. coli''. It is crucial when ''NhaA''’s activity is limited, such as ''NhaA'' is not sufficiently induced, or ''NhaA'' is not activated.
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''NhaA'' catalyzes the exchange of 3 protons per 2 sodiums. ''NhaA'' has a high affinity for sodium and lithium. Its activity is weakly pH-dependent, which is essential for regulation of intracellular pH under alkaline conditions. Therefore, ''NhaA'' could make sure ''E. coli''’s survival under alkaline pH, which are in desperate need of our project.
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''NhaB'' catalyzes the exchange of 3 protons per 2 sodiums.(Fig.2) ''NhaB'' has a high affinity for sodium and lithium. Its activity is weakly pH-dependent, which is essential for regulation of intracellular pH under alkaline conditions. Therefore, ''NhaB'' could make sure ''E. coli''’s survival under alkaline pH, which are in desperate need of our project.
  
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[[File:BIT_China_Resistance_System_pic2.png]]
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Fig.1 The mechanism of ''NhaB''
  
  
 
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===Usage and Biology===
 
===Usage and Biology===
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In the absence of ''NhaA'', ''NhaB'' confers a certain tolerance to sodium which decreases with increasing pH. Essential for regulation of intracellular pH under alkaline conditions, ''NhaB'' is crucial when the level of ''NhaA'' activity is limiting, when ''NhaA'' is not sufficiently induced, and/or when ''NhaA'' is not activated. Unlike ''NhaA'', the activity of ''NhaB'' shows no dependence on pH in the range 6.4-8.3. The affinity of ''NhaB'' to sodium (Km = 40-70μM) is higher than that of ''NhaA''.
  
 
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Revision as of 21:10, 18 September 2015

NhaB; sodium-proton antiporter; membrane protein

The gene, NhaB, is the archetypal sodium/proton anti-porter in E. coli. It is crucial when NhaA’s activity is limited, such as NhaA is not sufficiently induced, or NhaA is not activated. NhaB catalyzes the exchange of 3 protons per 2 sodiums.(Fig.2) NhaB has a high affinity for sodium and lithium. Its activity is weakly pH-dependent, which is essential for regulation of intracellular pH under alkaline conditions. Therefore, NhaB could make sure E. coli’s survival under alkaline pH, which are in desperate need of our project.

BIT China Resistance System pic2.png

Fig.1 The mechanism of NhaB


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BglII site found at 5
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 1003
    Illegal AgeI site found at 1315
  • 1000
    COMPATIBLE WITH RFC[1000]