Anaerobic Respiration - Exercise #1

You know that E. coli can respire using a variety of different electron donors. One such donor is formate, which is oxidized by one of two formate dehydrogenases, formate dehydrogenase-H (part of the formate hydrogen-lyase complex) and formate dehydrogenase-N.

  1. You are using EcoCyc to find out what possible substrate(s) E. coli can use as electron acceptors when formate is the electron donor? Name 3.


  3. Formate dehydrogenase-N is located in the cytoplasmic membrane with its catalytic subunits facing the periplasmic site.  Which protein secretion system translocates FDH-N to the periplasm?


  5. You specifically wish to look at formate hydrogenase-N (Fdh-N).  Under what environmental condition(s) is operon expressed maximally?