The role of the bacitracin ABC transporter in bacitracin resistance and collateral detergent sensitivity

The bacitracin resistance of Bacillus licheniformis, a producer of bacitrac in, is mediated by the ABC transporter Bcr. Bacillus subtilis cells carryin g bcr genes on high-copy number plasmids developed collateral detergent sen sitivity, as did human cells with overexpressed multidrug resistance P-glyc oprotein. Resistance against bacitracin and sensitivity of resistant cells to detergents were shown to be inseparable phenomena associated with the me mbrane part of Bcr transporter, namely protein BcrC. A fused protein, consi sting of ATP-binding protein BcrA and membrane component BcrC was construct ed. It resembled a half molecule of P-glycoprotein and was capable of provi ding a significant degree of antibiotic resistance and detergent sensitivit y. (C) 2000 Published by Elsevier Science B.V. on behalf of the Federation of European Microbiological Societies.