Conformational change in an MFS protein: MD simulations of LacY.

摘要: Summary Molecular dynamics simulations of lactose permease (LacY) in a phospholipid bilayer reveal the conformational protein. In inhibitor-bound (i.e., those closest to X-ray structure) protein was stable, showing little change over a 50 ns timescale. Movement bound inhibitor, TDG, an alternative binding mode observed, so that it interacted predominantly with N-terminal domain and residue E269 from C-terminal domain. multiple ligand-free simulations, degree closure occurred. This switched LacY state central cavity closed at both intracellular periplasmic ends. may resemble possible intermediate transport mechanism. Domain occurs by combination rigid-body movements domains intradomain motions helices, especially TM4, TM5, TM10, TM11. A intrahelix flexibility appears be important change.