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

ABSTRACT: 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 energy input in the form of the cytoplasmic membrane proton motive force is required to promote immunity protein (Im9) release from the colicin E9/Im9 complex and colicin cell entry. We report here that engineering rigidity in the structured part of the colicin translocation domain via the introduction of disulfide bonds prevents immunity protein release from the colicin complex. Reduction of the disu

SUBMITTER: Vankemmelbeke M 

PROVIDER: S-EPMC3831645 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature