Energetics of side-chain partitioning of β-signal residues in unassisted folding of a transmembrane β-barrel protein.

ABSTRACT: The free energy of water-to-interface amino acid partitioning is a major contributing factor in membrane protein folding and stability. The interface residues at the C terminus of transmembrane β-barrels form the β-signal motif required for assisted β-barrel assembly in vivo but are believed to be less important for β-barrel assembly in vitro Here, we experimentally measured the thermodynamic contribution of all 20 amino acids at the β-signal motif to the unassisted folding of the model β-barrel protein PagP. We obtained the partitioning free energy for all 20 amino acids at the lipid-facing interface (ΔΔG⁰_w,i(φ)) and the protein-facing interface (ΔΔG⁰_w,i(π)) residues and found that

SUBMITTER: Iyer BR 

PROVIDER: S-EPMC5519381 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature