From the Shewanella gurus. AFM analysis shows that MR-1 has an outer coating of decaheme cytochromes. Pretty neat stuff.
I’ve got a crazy idea… attach the lipid signal peptide of OmcA or MtrC to something like CymA and see if you can send it to the outer membrane.
Appl Environ Microbiol. 2009 Mar 13. [Epub ahead of print]
Antibody-recognition force microscopy shows that outer membrane cytochromes OmcA and MtrC are expressed on the exterior surface of Shewanella oneidensis MR-1.
Lower BH, Yongsunthon R, Shi L, Wildling L, Gruber HJ, Wigginton NS, Reardon CL,
Pinchuk GE, Droubay TC, Boily JF, Lower SK.
Antibody-recognition force microscopy showed that OmcA and MtrC are expressed on
the exterior surface of living Shewanella oneidensis MR-1 cells when Fe(III),
including solid phase hematite (Fe2O3), was the terminal electron acceptor. OmcA
was localized to the interface between the cell and mineral. MtrC displayed a
more uniform distribution across the cell surface. Both cytochromes were
associated with an extracellular polymeric substance.
PMID: 19286784 [PubMed - as supplied by publisher]
April 1, 2009 at 7:58 pm
Hi! I’m a journalist who’s interested in writing an article about Shewanella for the lay reader. Since the folks frequenting this blog seems to know way more about Shewanella than me (a non-scientist) I’m wondering if one of you would be willing to give me a little tutorial via email–in return for being cited prominently as a source. Won’t take much time, I promise; I know you’re busy.
Chris in Chicago
May 5, 2009 at 1:16 pm
Problem with the blogs is you say too much and my advisor thinks I’m giving away secrets :)
Assuming that they read blogs, which I hope they are not. Thats my job as a Phd candidate lol.
I think I will be a bad scientist one day because I will share too much and then get beat to publication. oh well.
All I’ve got to say is I’ll let the masses flounder over the ideas that their OM decahemes are TEAs while I sit back with my bugs in our easy chairs and let their chelators do the work! Now is that OM complex doing the reduction or is it internal, maybe CymA? thats the million dollar question. literally.
May 5, 2009 at 3:02 pm
Omc’s as TEA’s… I don’t think that has been shown in the sci. lit. There is some evidence that shows they are in the eps. It is clear that when you knock out certain omc/mtr’s iron reduction goes way down. The decahemes are doing something for the cell.
Now don’t forget the flavins and other redox active molecules secreted by Shewanella. This could be a major pathway for facilitating e- transfer to minerals.
I also don’t think CymA could be a directly reducing iron mineral unless CymA was expressed on the surface. In vitro it might reduce but not in vivo. I see where you are going with CymA… keep your secret under wraps… however I’d really like to know :-)
I appreciate your comments.
-c