西亚试剂：：Folding and Self-Assembly of the TatA Translocation

Torsten H. Walther, Christina Gottselig, Stephan L. Grage, Moritz Wolf, Attilio V. Vargiu, Marco J. Klein, Stefanie Vollmer, Sebastian Prock, Mareike Hartmann, Sergiy Afonin, Eva Stockwald, Hartmut Heinzmann, Olga V. Nolandt, Wolfgang Wenzel, Paolo Ruggerone, Anne S. Ulrich

We propose a concept for the folding and self-assembly of the pore-forming TatA complex from the Twin-arginine translocase and of other membrane proteins based on electrostatic “charge zippers.” Each subunit of TatA consists of a transmembrane segment, an amphiphilic helix (APH), and a C-terminal densely charged region (DCR). The sequence of charges in the DCR is complementary to the charge pattern on the APH, suggesting that the protein can be “zipped up” by a ladder of seven salt bridges. The length of the resulting hairpin matches the lipid bilayer thickness, hence a transmembrane pore could self-assemble via intra- and intermolecular salt bridges. The steric feasibility was rationalized by molecular dynamics simulations, and experimental evidence was obtained by monitoring the monomer-oligomer equilibrium of specific charge mutants. Similar “charge zippers” are proposed for other membrane-associated proteins, e.g., the biofilm-inducing peptide TisB, the human antimicrobial peptide dermcidin, and the pestiviral ERNS protein

丙烯醛肉桂醛桂皮醛4-硝基肉桂醛