Nutrient Transport - Exercise #7
You are studying nutrient uptake in E. coli and are curious about the PutP transporter (encoded by the putP gene).
- 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?
- What is the affinity of this transporter for its transported molecule(s)?
- 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)
- 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?
- Which amino acid residue (sequence number and full name) is responsible for binding sodium and proline?
- 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)