Looking for E. Coli compatible secretion markers.

Hi everyone, I'm looking for secretion markers compatible with e. coli and RiAFP, a beetle antifreeze protein.  Any info would be appreciated.  The ultimate goal is to make e. coli that secretes antifreeze into its immediate environment.


  • use the osmY standard part. it does the thing that you want to do. you can attach it to your c or n terminus, but it might work better on one side or the other so try it both.
  • Thank you.  I was also thinking about using a T3SS marker to utilize E. Coli's injectosome for protein secretion.  Do you know of the pros and cons to it?
  • Waaay more complex.
    Basically, the difference is T3SS is like "lets build this complex apparatus for moving something across membranes" while osmY is like "gurl (your favourite microbe), gonna make you sweat".

    If you were looking to inject something into another system, with a bit of specificity, sure, T3SS.
    If you just want to culture a bunch of microbes that leak a molecule, osmY is way easier.
  • Interesting!  But am I right in assuming that osmY is a promoter?  I've looked through the registry and NCBI and that seems to be the case; I haven't had any experience with osmY before, so I assumed it would be a marker of some sort.  How exactly does it work?
  • osmY is an osmatic protien, in that it allows a build up of whatever you are causing your cells to produce to get outside the cell so that it doesn't become unbalanced. you attach osmY to your sequence of choice. say it's the GFP sequence as a marker and AFP for effect. your control is GFP with AFP, no osmY. I assume you know how to staple them together and insert them. that's not the point of this bit here....

    you grow up your two cultures, spin them down, and pull off the supernatant. no osmY glows only very faintly. most the GFP-AFP was internalized in the bacteria, and was removed from the liquid when you pelleted them out. the growth medium for osmY-gfp-rfp glows much brighter, due to the fact that the cells are osmatically leaking GFP-AFP into the medium.
  • Okay, I see.  Very cool.  Thanks for all of your help!
  • np. just happy to be talking about biology. 
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