The crystal structure of the TonB-dependent transporter YncD reveals a positively charged substrate-binding site

Abstract

The outer membrane of Gram-negative bacteria is highly impermeable to hydrophilic molecules of larger than 600Da, protecting these bacteria from toxins present in the environment. In order to transport nutrients across this impermeable membrane, Gram-negative bacteria utilize a diverse family of outer-membrane proteins called TonB-dependent transporters. The majority of the members of this family transport iron-containing substrates. However, it is becoming increasingly clear that TonB-dependent transporters target chemically diverse substrates. In this work, the structure and phylogenetic distribution of the TonB-dependent transporter YncD are investigated. It is shown that while YncD is pr..