Interesting paper on the tetraheme cytochrome has just been published. Authors show that the CymA cytochrome has iron reductase activity when expressed in E. coli. They propose that this has given E. coli the ability to respire iron(III). That is, E. coli can conserve energy from reducing iron and grow on it too. This is normally not the case. Here is the link to the paper in Pubmed:
Dissimilatory iron reduction in Escherichia coli: identification of CymA of Shewanella oneidensis and NapC of E. coli as ferric reductases.
Gescher JS, Cordova CD, Spormann AM.
