Comparative approach is a powerful tool for analysis of gene regulation in bacterial genomes. Here we apply it to analysis of regulation of the multidrug resistance transport (MDRT) systems in enterobacteria Escherichia coli, Salmonella typhi, Klebsiella pneumoniae and Yersinia pestis. Comparison of nucleotide sequences upstream of MDRT genes was performed in order to predict new regulatory sit...

Acinetobacter baumannii is an opportunistic pathogen, causing infections mainly in patients in intensive care units where the extensive use of antimicrobial agents can select for the emergence of multiresistant strains. In fact, since strains resistant to all antimicrobial agents have been reported, A. baumannii is considered the paradigm of multiresistant bacteria. Both acquired and intrinsic ...

The purified outer membrane proteins of Pseudomonas aeruginosa were reconstituted with phosphatidylcholine and dicetylphosphate into membrane vesicles, and these were tested by the liposome swelling method for the diffusion of saccharides with different Mr. Proteins C (Mr, 70,000), D (Mr, 46,000), and E (Mr, 43,000) were found to confer the monosaccharide-permeable pores in the reconstituted li...

The outer-membrane proteins (OMPs) of bacteria function as the dynamic interface between the bacterium and its surroundings and are involved in maintenance of cell structure, binding a variety of substances, adhesion to other cells, and regulation of transport of both nutrients and bactericidal agents. There is a vast amount of information about aerobic OMPs and their roles in immunogenicity, v...

When grown at acidic pH, Escherichia coli cells secrete cadaverine, a polyamine known to inhibit porin-mediated outer membrane permeability. In order to understand the physiological significance of cadaverine excretion and the inhibition of porins, we isolated an OmpC mutant that showed resistance to spermine during growth and polyamine-resistant porin-mediated fluxes. Here, we show that the ad...

Crystallographic studies of the past ten years have revealed that many outer membrane proteins and bacterial toxins are constructed on the beta-barrel motif. Two structural classes can be identified. The first class, represented by the porins, includes monomeric or multimeric proteins where each beta-barrel is formed from a single polypeptide. The second class features proteins where the beta-b...