It has long been suggested that the import of nuclease colicins requires protein processing; however it had never been formally demonstrated. Here we show that two RNase colicins, E3 and D, which appropriate two different translocation machineries to cross the outer membrane (BtuB/Tol and FepA/TonB, respectively), undergo a processing step inside the cell that is essential to their killing acti...

Cross River serves as a major source of drinking water, transportation, agricultural activities and fishing in Cross River State, Nigeria. Since there is no formal control of effluents discharged into the river, it is important to monitor the levels of metals contaminants in it, thus assessing its suitability for domestic and agricultural use. In order to determine this, three sampling stations...

Both induction of transcription of the ferric citrate transport genes and transport of ferric citrate by the Escherichia coli outer membrane receptor FecA require energy derived from the proton motive force (PMF) of the inner membrane. The energy is transduced to FecA by the inner membrane complex, TonB, ExbB, and ExbD. Region 160 of TonB and the conserved TonB box of other TonB-dependent recep...

BACKGROUND Pathogenic Escherichia coli infections cause various diseases in humans and many animal species. However, with extensive E. coli vaccine research, we are still unable to fully protect ourselves against E. coli infections. To more rational development of effective and safe E. coli vaccine, it is important to better understand E. coli vaccine-associated gene interaction networks. MET...

To better understand Fe cycling in marine and freshwater systems, we have developed a biomolecular tool to track the perceived bioavailability of Fe to heterotrophic bacteria. Bioluminescent reporters, constructed by fusing the fepA–fes promoter of Escherichia coli (an Enterobactin biosynthesis gene regulated by the ferric uptake regulatory [Fur] system) to a luxCDABE cassette, were integrated ...

The study investigated the levels of six trace metals V, Cu, Pb, Cd, Fe and Ni in surface sediment of Kalabari creeks. Surface sediments of about 0-2cm depth were collected from June 2009 to April 2010 at two months interval to cover the rainy and dry seasons. Bulk scientific atomic absorption spectrophotometry (AAS) model 200A was used to analyze the samples. The results obtained revealed that...