Nutrient Transport - Exercise #7

 You are studying nutrient uptake in E. coli and are curious about the PutP transporter (encoded by the putP gene).

  1. What molecule(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?

  3. What is the affinity of this transporter for its transported molecule(s)?

  5. Is the transcription of the transporter gene regulated?  If so, what protein(s) regulate it?  If regulated, how many DNA regulatory sites total (for the promoter) are there?  (Hint:  Look at the “Transcription Units” diagram)

  7. When viewing the transport diagram, where is the transporter localized? How many membrane-spanning regions does it have?  On what side of the cytoplasmic membrane are the N and C termini located?

  9. Which amino acid residue (sequence number and full name) is responsible for binding sodium and proline?

  11. Is this gene part of an operon?  If so, what other gene(s) is/are in the operon?  Give the gene(s) function also, if applicable (Hint:  click on the genome browser)