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Nutrient Transport - Exercise #6

You are studying nutrient uptake in E. coli and are curious about the transporter encoded by the gene nupC.

  1. What is the name of this transporter and what nucleoside(s) does this transporter transport into the cytosol and/or periplasmic space?  Establish what category (Passive Diffusion, Facilitated Diffusion, Active Transport).  Establish what class (Ion Driven - be specific, Group Translocation, ABC Transporter) of transporters it belongs to.  What energy source, if any, drives the uptake process?
  2.  

  3. Is the transcription of the transporter gene regulated?  If so, what protein(s)/ molecule(s) regulate it?
  4.  

  5. When viewing the transport diagram, where is the transporter located?  How many transmembrane helices does it have (Hint:  Look at the Sequence Features diagram)?
  6.  

  7. Why would the cell import nucleosides?
  8.  

  9. What sigma factor is required for binding RNA polymerase to the promoter for transcription initiation?