Autoprocessing of the Escherichia coli AIDA-I autotransporter: a new mechanism involving acidic residues in the junction region.

ABSTRACT: The cleavage of the autotransporter adhesin involved in diffuse adherence (AIDA-I) of Escherichia coli yields a membrane-embedded fragment, AIDAc, and an extracellular fragment, the mature AIDA-I adhesin. The latter remains noncovalently associated with AIDAc but can be released by heat treatment. In this study we determined the mechanism of AIDA-I cleavage. We showed that AIDA-I processing is an autocatalytic event by monitoring the in vitro cleavage of an uncleaved mutant protein isolated from inclusion bodies. Furthermore, by following changes in circular dichroism spectra and protease resistance of the renaturated protein, we showed that the cleavage of the protein is correlated with folding. With site-directed deletions, we showed that the catalytic activity of the protein lies in a r

SUBMITTER: Charbonneau ME 

PROVIDER: S-EPMC2719369 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature