[1] Univ Texas Arlington, Dept Biol, Arlington, TX 76019 USA
[2] St Jude Childrens Res Hosp, Dept Chem Biol & Therapeut, Memphis, TN 38105 USA
[3] Univ Leeds, Antimicrobial Res Ctr, Leeds LS2 9JT, W Yorkshire, England
[4] Univ Leeds, Inst Mol & Cellular Biol, Leeds LS2 9JT, W Yorkshire, England