Peptides and ATP binding cassette peptide transporters.

In this review our knowledge of ATP binding cassette (ABC) transporters specific for peptides is discussed. Besides serving a role in nutrition of the cell, the systems participate in various signaling processes that allow (micro)organisms to monitor the local environment. In bacteria, these include regulation of gene expression, competence development, sporulation, DNA transfer by conjugation, chemotaxis, and virulence development, and the role of ABC transporters in each of these processes is discussed. Particular attention is paid to the specificity determinants of peptide receptors and transporters in relation to their structure and to the mechanisms of peptide binding.