Structure-Function Analysis of the Periplasmic Escherichia coli Cyclophilin PpiA in Relation to Biofilm Formation

The presence of peptidyl-prolylcis/trans isomerases (PPIases, EC: 5.2.1.8) in all domains of life indicates their biological importance. Cyclophilin PpiA, present in the periplasm of gram-negative bacteria, possesses PPIase activity but its physiological functionsare still not clearly defined. Here, we demonstrate that the #x0394;ppiA deletion strain fromEscherichia coli exhibits an increased ability for biofilm formation and enhanced swimming motility compared to the wild-type strain. To identify structural features of PpiA which are necessary for the negative modulation of biofilm formation, we constructed a series of mutant PpiA proteins using a combination of error-prone and site-directed mutagenesis approaches. We show that the negative effect of PpiA on biofilm formation is not dependent on its PPIase activity, since PpiA mutants with a reduced PPIase activity are able to complement the #x0394;ppiA strain during biofilm growth.J Mol Microbiol Biotechnol 2017;27:228-236
Source: Journal of Molecular Microbiology and Biotechnology - Category: Microbiology Source Type: research