Vankemmelbeke, Mireille and Housden, Nicholas G. and James, Richard and Kleanthous, Colin and Penfold, Christopher N. (2013) Immunity protein release from a cell-bound nuclease colicin complex requires global

Vankemmelbeke, Mireille and Housden, Nicholas G. and James, Richard and Kleanthous, Colin and Penfold, Christopher N. (2013) Immunity protein release from a cell-bound nuclease colicin complex

Immunity protein release from a cell-bound nuclease colicin complex requires global conformational rearrangement

Nuclease colicins bind their target receptor BtuB in the outer membrane of sensitive Escherichia coli cells in the form of a high-affinity complex with their cognate immunity proteins. The release of the immunity protein from the colicin complex is a prerequisite for cell entry of the colicin and occurs via a process that is still relatively poorly understood. We have previously shown that an e...

Rapid detection of colicin E9-induced DNA damage using Escherichia coli cells carrying SOS promoter-lux fusions.

ColE9 is a plasmid-encoded protein antibiotic produced by Escherichia coli and closely related species that kills E. coli cells expressing the BtuB receptor. The 15-kDa cytotoxic DNase domain of colicin E9 preferentially nicks double-stranded DNA at thymine bases and shares a common active-site structural motif with a variety of other nucleases, including the H-N-H homing endonucleases and the ...

Cell entry mechanism of enzymatic bacterial colicins: porin recruitment and the thermodynamics of receptor binding.

Binding of enzymatic E colicins to the vitamin B12 receptor, BtuB, is the first stage in a cascade of events that culminate in the translocation of the cytotoxic nuclease into the Escherichia coli cytoplasm and release of its tightly bound immunity protein. A dogma of colicin biology is that the toxin coiled-coil connecting its functional domains must unfold or unfurl to span the periplasm, wit...

Investigating early events in receptor binding and translocation of colicin E9 using synchronized cell killing and proteolytic cleavage.

Enzymatic colicins such as colicin E9 (ColE9) bind to BtuB on the cell surface of Escherichia coli and rapidly recruit a second coreceptor, either OmpF or OmpC, through which the N-terminal natively disordered region (NDR) of their translocation domain gains entry into the cell periplasm and interacts with TolB. Previously, we constructed an inactive disulfide-locked mutant ColE9 (ColE9(s-s)) t...