9.A.8.1.10
FeoABC Fe²⁺ transporter (Hung et al., 2012). FeoA is a 75 aa protein homologous to the N-terminus of FeoB2 of Porphyromonas gingivalis (TC#9.A.8.1.6) and with some sequence similarity to an internal hydrophilic segment of the RND heavy metal porter, CzcA of Myxococcus xanthus (TC#2.A.6.1.7). Linkous et al. 2019 have determined the crystal structure of FeoA from Klebsiella pneumoniae (KpFeoA). The structure reveals an SH3-like domain that mediates interactions between neighboring polypeptides via hydrophobic intercalations into a Leu-rich surface ridge. Using docking of a small peptide corresponding to a postulated FeoB partner binding site, they demonstrated that KpFeoA can assume both "open" and "closed" conformations, controlled by binding at this Leu-rich ridge. They propose a model in which a "C-shaped" clamp along the FeoA surface mediates interactions with its partner protein, FeoB (Linkous et al. 2019).