The YompC protein of Yersinia enterocolitica: molecular and physiological characterization.

The structural gene coding for YompC has been identified in the genome of a pathogenic strain of Yersinia enterocolitica O:9, and was subsequently cloned and sequenced. Detailed alignment of the deduced amino acid sequence showed that YompC is a member of the OmpC porin family with the highest degree of homology to Klebsiella pneumoniae. The mutant lacking YompC porin was constructed by insertional inactivation of the yompC gene which resulted from the integration of suicide vector at the yompC locus. In intact cells of Y. enterocolitica, loss of the YompC protein reduced the outer membrane permeability for beta-lactam antibiotics and tetracycline and resulted in a 2-5-fold increase in resistance to these compounds, depending on their chemical properties. Mutation in the ompR regulatory gene resulted in the loss of both YompC and YompF porins, which led to a greater increase of resistance to antibiotics, as compared with the YompC mutant strain. Moreover, the binding assay with HEp-2 cells suggests that YompC may play a role in the adhesion properties of Y. enterocolitica strains.