Susceptibility of Escherichia coli to the toxic L-proline analogue L-selenaproline is dependent on two L-cystine transport systems.

Aims: L-Selenaproline (L-selenazolidine-4-carboxylic acid) is a toxic analogue of L-proline that inhibits the growth of the urinary tract pathogen Escherichia coli in both laboratory culture media and normal human urine. The aim of this study was to identify the transport systems involved in its uptake.

Methods And Results: Deletion mutants from the Keio collection were tested for their susceptibility to L-selenaproline (SCA) and L-selenocystine (SeCys) on minimal salts agar medium.