Slipknotted and unknotted monovalent cation-proton antiporters evolved from a common ancestor
Fig 3
Structure of the slipknotted transporter KpCitS.
(A) Location of the knotted core (N115-N401) starts at TM4 of domain A, loop-linker and TM8-TM11 and half of TM12 hairpin-like helix of domain B. Slipknot loop (R402-S421) is formed by half of TM12 hairpin-like helix and part of TM13. The rest of TM13 (residues Y422-I446) is slipknot tail. (B) Schematic representation of the slipknot topology. (C, D) Structure of the knotted core and slipknot’s loop and tail based on PDBID 5xar. (E) Knot fingerprint calculated based on the KpCitS structure (PDBID: 5xar).